They are so far apart in terms of rules/eras that it's hard to say. In terms of raw ability, Corbett is the smoother operator, but he had a remarkably small resume for an old timer. It could end up resembling the Tillis fight imo.
I think Shavers technical proficiencies are somewhat underrated in order to emphasise his raw punching power. A switched on, focused Shavers knew how to deliver the defining punches in the early rounds - and Shavers had that long reach and fast hands. Of course beyond the mid way point Shavers chances progressively diminish somewhat but I personally find it hard to imagine Jim lasting beyond the first third of the fight (so < 5 rounds given a 15 rounder). Finally, I’m very proud of myself for not once mentioning Jim’s g-string for cheap laughs.