[JimStinson]

The signatures are a mute point , As the photo itself which appears to be an original "Dana" would have far more value than the Autographs. If they are real or not and in my opinion they are not. The "fight" on the other hand was arguably "The Fight of the Century" And an original photo from the "set" that was taken throughout the bout is a nice find.

The Jeffries matches nether his signature or writing style.
In addition the signature of Jack Dempsey on the photo would have no more relevance to the event than if Mae West had signed it. Have attached a couple Dempsey Vintage sigs to go with the one someone posted above that was signed later in life and one common thread to make note of is that the "end" portion of Dempsey on the "Dana" photo is clearly formed , look at the "sey". , On almost all of the Dempsey signatures I have ever seen he does not include a pronounced "s" , siging his last name to look more like "DEMPEY" than "DEMPSEY".