Young Joseph is physically faster, stronger, smarter, and has better Hamon and equipment.
He still loses, because the Golden Oldie has Hermit Purple. It's a weak Stand, but what's often forgotten is Stands can only be harmed or interacted with by other Stands. In other words, if Oldie gets one single HP vine around Young Joseph's ankle or wrist, he literally can't move. He can't fight it whatsoever. He could be as strong as the Hulk (theoretically) and still be perfectly roped in place. For this reason, with speed equalized, even Part 4 Joseph would probably beat Young Joseph.
I know this is a bit of a necro, but I'm just trying to get this thread closed and the victory added. My vote goes to the world champion GILF.