I have to say that many people have been extremely generous with their photos, information, etc. A number of regulars on this forum have provided many photographs that filled in the holes in my collection. My K-28 book will have a long list of contributors who asked not a dime, just want a copy of the book. I was fortunate to have completed all the research I needed for the K-37 and K-28 books before some of the doors were closed.
My research materials and photographs will be preserved when I am gone. Perhaps some day someone will complete the work I have started.