Thanks, Ursa. We put a lot of work into the cover.
Actually, it was in the box I had earlier expected it to be, a photo box covered in paper with a Victorian flower motif. The problem is, I have many such boxes. All the rest were in my bedroom/office. One held rolled-up pairs of socks, one held hats knitted by my late mother, one held office supplies, etc. I had, of course, examined them all ... many times. "Yup, still socks. Yup, still hats." They never changed overnight, no matter how many times I checked.
I didn't know there was another box half-hidden by books on a lower shelf in the hall, put there when Eric died and Gwyneth moved home, so that we had to shift everything around (again).
When I found it, I lifted the lid, literally with trembling hands. Inside were letters from my agents, contracts, etc., dated 1994-1995. I kept telling myself, "Don't get excited, don't get excited. It might not be here. Don't get excited."
Except it was there.
I don't know why I suddenly noticed the box peeking out from the books, when I must have passed it thousands of times without seeing it. It was two feet from my bedroom door, all the time that I was conducting frantic searches through drawers and boxes filled with musty old manuscripts, notebooks, birthday cards, book covers, pictures drawn by my children when they were small, and so forth.
It was actually fortunate (no matter how traumatic) that I didn't find it earlier, because if I hadn't contacted my ex-publishers I would never have known that they didn't have a record of the reversion letter and still thought they owned the rights. That could have led to unpleasantness later, so it's good to clear it up now.
So maybe somebody's prayers worked.
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