I would give it to Jeffries because he was taking the kind of beatings that would not have been alowed in Marciano's era and coming back to win.
do you think there is any truth to the rumors that bob fitz had loaded gloves on and jim still beat him?
I think that the evidence is not suficient to definitely establish it one way or the other. After the fight Bob Fitzsimmons was challenged and he threw his glove into the crowd with the result that it was never recovered. There was obviously something not right about the glove but it could have been something minor.