I can't imagine them finding too many prints with this historic significance 150 years from now, considering most people shooting digital don't print. Something seeming so ordinary at the time might just be deleted never to be seen again.
My own personal and biased opinion. The "Brady" is a fake.
1) Why fake a Wilson? No monetary gain.
2) You can't fake a stereo photograph, but you can easily take one of the stereo images as a non-stereo. (that is a real stereo pair).
Rhetorical question, so if it were faked by Brady's gang for Brady is it still an original Brady...?
I guess years from now historians will be trying to figure out "is it Richard Prince or Jim Krantz?" whenever someone finds an old cigarette ad in the attic...
In keeping with true internet speculation and non-substantiated opinion, I wonder who got the $30,000, the deceased owner??
New York collector Keya Morgan said he paid $30,000 for the photo album including the photo of the young boys and several family pictures and $20,000 for the sale document. Morgan said the deceased owner of the home where the photo was found was thought to be a descendant of John [boy in picture?].
And why fake a sale? Well, maybe a museum would pay you what you have invested in a piece:
Morgan said, he is keeping the photo in his personal collection, but he said he has had an inquiry to sell the photo to the Metropolitan Museum of Art.