I think you would definitely enjoy Birmingham's Axis of time Trilogy.
I am currently rereading Axis of Time. There was a fantastic and epic sized Alternate History over on the Alt History Forums, written by one of the Users (I have only been able so far when looking recently to locate what appears to be a vastly reduced edit not the original I read 4 years ago) The United Kingdom and Republic of Ireland of 2010 are thrown to 1940. (I think it's the Republic, it may have just been the UK and NI, with the downtime Irish Free State remaining in place but I have vague memories it may have been the modern Republic because I am sure its pharmaceutical industry is off massive help to the UK)
The Transition Downtime occurs immediately, the Government worried there has been a terrorist strike or some sort of global disaster knows something has happened, simply because all the Satellites, internet & telephone fibre optic trunk lines linking the UK to the rest of the world have all gone down, not to mention, things like French radio signals have vanished, and the Air Traffic Controls Centres are making contact in panic and uproar because the dozens of planes they were tracking midway over the channel, and to the West, North and South of the Country have simply vanished, along with their linkups to european traffic controls. In Geographical terms, the entirety of the Island of Great Britain, all its Islands, Scottish, Wight, Isle of Man etc have been sent back, and I think all the oil rigs of the British Oil sector of the North Sea, which means in the plus side, those rigs are suddenly sitting in the identical geographic place, but the Oil deposits have now been refilled to basically untapped 1940 levels.
A British Airways plane, heading for Paris was just within the Transition zone when it happened, and having lost contact with French ATC, and iirc the plane suffering electronic malfunctions from transiting manages a crash landing just outside a town in Normandie. Which means of course, within minutes, the shocked passengers think they have crashed in the midst of a major historical movie production, because there's grim looking chaps in WW2 Wehrmacht uniforms, Armoured transports and Kubelwagens approaching
Then of course, baffled and panicky telephone calls begin coming in from Greater Manchester Police, Terrorists in antique Aeroplanes are overflying the city and dropping bombs, 1 plane suffers damage, Pilot bails, and GMP Interceptor Constables have a shootout with the landed "Terrorist" who is dressed in ww2 style german uniform and is armed with a luger.
Just like in Axis of Time, despite the serious technology imbalance, it's not going to be a case of once its understood what is going on, of sending some Squadrons of Royal Air Force Typhoons, which the Luftwaffe couldn't even keep in range, speed terms, when at full speed to drop large modern and highly destructive munitions with pinpoint accuracy over Berlin and destroy the senior command and control infrastructures and Officers, not to mention one on wherever Hitler is according to the history books, and some bunker busters down on his infamous bunker to deny its use. With modern supply lines lost, the RAF, and the rest of the British Forces only have a finite amount of modern munitions, and spare parts, since its all mostly brought from abroad, Britain not having much of a weapons manufacturing industry, not in terms of stuff that will work with current issue British kit, I imagine Ammunition for SA80 Assault rifles etc could be sorted, since we do manufacture and sell guns and I assume ammo, much of which will be NATO Standard, in calibre etc.
Plus a British Airways Plane full of modern technology, not only that within the Plane itself, but the Passengers of course all have mobile phones, laptops, tablets, and I think a History Professor or Student who's tech is full of downloaded Historical Ebooks and files regarding WW2. So Hitler is going to have a pretty shrewd idea very soon which Generals, and Party men, etc to immediately order to be liquidated, and have a full list of his personal inadequacies, health issues, and many, many mistakes.
It's a fun ride. The Son of a white British MP who has converted to Islam to marry his love, conceives an idea to stabilise the middle east for ever more, the Government approves it, he recruits a small Army of Moderate Muslim Volunteers, get's equipped and trained by the British Army, then the Royal Navy which is probably capable of wiping out not just the Kriegsmarine, wherever it may be, but the entire 1940 US Navy, should they desire, and have enough munitions transports them and they carry out an unopposed Landing in Saudi Arabia.
In 1940, the Saudi's and their Royals, whilst the modern Kingdom was founded in 1932 by the Al Saud's, placing themselves on the new throne, the SA of 1940 is still a highly tribal society, and the King's epic sized Family, and his "Army" are basically brigands and bandits on Horsies with 1920's and older weapons. The Moderate Muslim Army immediately begin combat Operations, and swiftly turn the main Royal Army who come charging out of Riyadh into a mess of mangled human and horsie flesh carpeting the desert. They then continue to engage and destroy (iirc they don't take surrender, to a Moderate British Muslim of 2010, the Saudi Arabia of 2010 is an evil barbaric State, the 1940 one is even more so, as far as they are concerned these soldiers are enemies of Allah, corrupting his will for their own evil ends, and no mercy is shown. They then proceed to hunt down and exterminate the male line of the Al Saud family, how ever many hundreds or thousands of Princely members etc the family had back then, though iirc they stop short of murdering Children, they aren't Monsters, they are helping to save the World of now, and the Future from Monsters. The new Nation they begin to build will be a liberal democracy, no Shariah law, with a Defence Force capable of smashing anything the rest of the Middle East can throw at them, numerical superiority doesn't mean much when that Defence Force is using 21st Century Combat Doctrine and Tactics, knows from the history books they bring the exact forces that could be brought to bear against them, and is armed with Assault Rifles, RPG's, Light and Heavy Machine guns, and 21st Century military grade body armour, versus armies that are generally not particularly professional, and are carrying bolt action rifles. Plus, some of the potential threats of 2010 don't yet exist, Egypt for example is iirc a British Controlled Mandate in 1940, as it Iraq/Mesopotamia. The idea is a well defended Democracy of moderate Muslims controlling the most Holy sites of Islam, such as Mecca, and without Saudi Arabia and the Al Sauds and other rich Saudi's they are basically exterminating Fundementalist Islam, and the powers that created and funded it, Saudi Wahabbism etc. I cant recall if they restrict themselves to Saudi, or if they take other places, and attack without Mercy anyone else they think could be a trigger for middle eastern instability and terrorism. I think Israel is pretty much not going to happen, except as a Democratic State of Palestine, its 1940, so there is time to stop the Extermination in the Nazi Camps.
It even has a Conspiracy with a couple of Cabinet Ministers and some senior Royal Navy Men (Cameron knows nothing about it) Britain to the US of course is "Airship One" and home to several US Bases, and plenty of US Technology, being as its 1940, the USA itself is not in the War yet, and the RAF and People are quickly coming to terms with the fact the Blitz is about to begin, and Cities all over the UK, including London are going to come under heavy Luftwaffe Attack, night after night, so to the Government, that US Technology, which includes iirc a couple Stealth Bombers.
The US Ambassador (2010) is told that any Americans who wish to return to the States, a cruise ship will be prepared at Liverpool to transport them, but they are not taking any technology or military hardware, and certainly not books, Laptops, tablets and so on, filled with ebooks and diagrams and technology blueprints etc, the UK has no intention of letting the US get any more leg up than what it may get from talking to 2010 US Citizens who arrive, No more American Empire and certainly no bankrupting the British Empire with crippling loans for "helping" (I wonder when we will be sending the invoice for Iraq and Afghanistan, should write of a significant amount of what we still owe and pay yearly from ww2 snigger) if Cameron can help it. The other condition is any US Civilian or Military Citizens who do not wish to return to the States will be given British Citizenship if they swear the Oath to the Crown, and for the military personnel and science/technical support staff, jobs are open for them in the British Forces, because of course, a significant number of those Citizens including senior officers, and technical geniuses are going to be Black, Asian, Native American, Gay, many Liberal, not to mention White Liberals, and the US of 1940 is an alien planet, they won't be able to cope with living on, especially since the ethnic and sexual minorities will lose all the rights and liberties they have grown up with, Liberals may as well sign in to a comfy 2010 UK Prison as sail 2000 miles and have Hoover do it to them, but with 1940 standards.
Many, including pretty much every single Minority and a good deal of more liberal Military Personnel, including Pilots, and the US Forces on base civilian technical support staff choose to stay. The rest are put on trains to Liverpool, board the cruise liner, which sets off, leaves Liverpool Docks, and as it reaches the Irish Sea, and starts hitting sea with significant depth, a "Kriegsmarine Uboat"who is not detected closing in, nor swiftly exiting torpedoes the Liner, which basically explodes and sinks with no survivors... the effect of the Torpedos seem incredibly powerful, almost as if they were beyond what any Navy had in 1940..... That is the conspiracy between some Ministers and RN personnel. A 2010 Royal Navy Sub has committed the Act, these people who saw themselves as thinking ahead and protecting the Empire, they now have a chance of keeping, don't want the 1940 US Military, Government Scientific and Technological Agencies, and US Industry getting access to all the information and secrets held in the returning 2010 personnel's heads, as it will still give the US a boost, even without samples of the actual technology. There is much, much more, like I say it was huge!!! I think Poland gets liberated early on, since the Wehrmacht & Luftwaffe don't cope terribly well with heavy precision bombings by jets their radar can barely see, not to mention the naked high, if bombing from height, followed by Her Majesty's Royal Marine Commandos, and 16 Air Assault Brigade, Elite troops trained to 21stC standards, and benefiting from 21stC Free NHS health care & medicines, armed with assault rifles, body armour, and using Assault Helicopters and Chopper Transports to engage, outwit, destroy, and outflank the enemy.
