As you say Lyn,the copyright laws are a very grey area.
I have the Images of Birmingham Books,Saltley and Duddeston by Maria Twist and others about Erdington,Coleshill etc.I note inside it says that no portion of the book can be reproduced without the permission of the publishers, but I have seen some of the images out there on the internet.
I would think that in the case of photos they would have to prove you took the image from their publication.