Hello Larry,
If hope you don't mind my saying it, but I think (as you were mentioning ebooks) that all non-relevant photos, for example, would make great reference books for modelers and researchers. I work in book publishing and I can imagine you groaning at the thought of more work when it's clear you are up to your eyeballs already, but I, personally, would pay $20.00 to $30.00 US for a book of unpublished photos that showed good detail, codes and markings.
I know the market would be small, but if say, Europe would be a better market then the contents could go to a publisher in England, who would then assemble the captions and do the layout. Since foreign shipping is always an issue for those in the States, perhaps you could do an American run with Eagle Editions.
Just a few thoughts. And I do hope you are taking the time to eat and drink between all the work
Best regards,
Ed