[Franz von Werra]

I saw some pictures of WWII aircraft being offered for sale on the Web. As I inquired on their origin I was told that they come from the archive of a defunct aviation magazine. Since many of you are authors, I think you handle copyright issues on a regular basis, so I am asking you for advice. The photos are printed (not magazine scans) on period paper and date back to 1944-45 circa. They would be great for the layout of one of my feature articles, but I would feel very uncomfortable in acquiring them for my own purposes without knowing exactly who they belong to. This is a riddle for me since I usually resort to getting in touch with the owner and asking for permission, or to using public domain pictures. I know most WWII pictures are Crown or IWM Copyright, so I really wouldn't like to run across a lawsuit should somebody feel hurt by my "liberties".
So what should I do?