Totally agree with your post. Not only (as you posted...)..." that they should be in a separate category " but I would add...in a different box in the main page. Why dont use the "Random Photo of the day" box ( for example ) for third party shots, collections, or photos not taken by the actual photographer ?.
Its just one idea...where to place those third party shots...
There is already some tolerance for older images that are scanned, this does not need to change in my opinion.
We must be sensible, the advances of digital photography are impossible to reproduce except from transparencies of exceptional quality.
Older images are very much admired on the site by a lot of the members.
Older images are indeed most interesting. But if these were not taken by the actual member who posts them on Shipspotting (of course with the proper copy right) it is my opinion that they should be in a separate category.