Hi,
Pardon the promotion, but this photo also appears in our biography of Kurt Bühligen, which can be downloaded here:
http://airwarpublications.com/earticles/biographies/
As for your question, no, I don't think you're doing anything wrong by saving photos from eBay and storing them on your computer for your own use.
Cheers,
Andrew A.
Air War Publications -
www.airwarpublications.com/earticles