I still have faith in the book manuscript, but am going to try a different means of promotion. Without the blessing of the editor, a lengthy memoir doesn't seem feasible. What I've chosen to do instead is to combine together existing chapters into a short story or two. If I can't get a full table out of the material, I'll be glad to take a chair.
As soon as I'm back to full speed and recovered from surgery, I'll begin this sort of work en masse. I've already sent out one such manuscript excerpt and will find other combinations and pairings. I have confidence in myself and my writing. By no means am I ready to abandon the vast amount of effort and time I've put into this work. Sometimes you have to improvise.