IMHO it is not possible that the ebay-seller has the originals even if he writes in the description that "the photo-paper is old
And you have examined of course. Bought one and so on..test paper. Examined wich copy it was or perhaps from what archive it came from or what collector/writer is disolving his archive.
I bet now a fine..fine whisky you have not.
So it is an opinion. Nothing more. You did say so in a way one might can read something else in it.
Btw if you have followed my eBay trawls you will see that sometimes known pictures are now on the back have writing on them.
In period script. And that later copies have not. Even published ones in well known books And sometimes with translation mistakes.
Now..what is the original now?
Furthermore a negatieve can host a lot of copies. Again please view my eBay trawls.
Being published is nice but do not mean anything. It does not mean other copies of the original negatieve do nor float around.
It was common practice. Allied or axis.
Ask me how I know after 30 + years of looking at those eBay pictures. And archives. Daily. Every day.
So I think it is quite a bold statement you made.