If there's not a photo then it didn't happen?
This whole thing could've been resolved decades ago.Just start with any photo of Oswald taking the shot.
While I don't know the exact number of photos that that show the rifle to be a model 91/38 Mannlicher Carcano, I'd guess there are at least two dozen.....But there isn't a single photo that shows a 7.65 Mauser at the TSBD that afternoon.
The rifle? Why would you assume there was exactly one?
Well, that would be Walt Fabrication #3, wouldn't it?