The sci-fi novel was a small paperback published before 1979 ... from memory the cover was a classic sci-fi cover from the 50's or 60's. The basic plot revolved around a house on earth that was used as an interplanetary train station that allowed interplanetary travellers to stop there before heading onto differnent planets. The "station master" was an old man who had been given longevity and was over a hundred but looking 60 or so. His House looked rundown but its exterior had been treated so it was impervious to aging. As part of the package for him to allow aliens thru he had a room in his house especially designed for his amusement and recreation .. a round room that allowed him to use it a holigraphic room to allow him to generate different environments for him to go hunting in ... much like the Star Trek holographic deck. A younger earthen happens across this older man thru some outstanding bill or something that he inadvertantly discovers the old man is a lot older that he appears. Any help to give me the title would be appreciated.