Duh. Now I noticed the reply button.
Thanks for your further info. I was asking on behalf of a friend who is writing and preparing for publication (500 to 1,000 copies) a book which involves the history of Birmingham. I collaborated with her on its editing. My chum is only likely to cover her publishing costs, so it's about as close to a non-commercial issue as you can get. But as proper, she asked my help in figuring out if a copyright owner could be ascertained, when she located those pics on your site.
My feeling is that a typical disclaimer should be included in "notes on the illustrations" to read something like "every effort has been made to try to identify the owner of copyright. If a copyright has been violated, or is incorrect, the author should be contacted so that further correction may be added to an subsequent edition published." I think that should cover it legally, and have so suggested to her. Thank you again. Brenda