If Joe fights to the best of his ability and keeps his workrate up he decisions George. His jab is the primary weapon here.
I’m not certain. Joe Bugner was a decent boxer with good survival and defensive skills. He’d also have some height and reach over chuvalo. But George was durable and could punch a bit. And I don’t think Bugner had much to deter him with. Chuvalo would most likely be the aggressor which might help him on the scorecards a little. I’m fairly certain this goes the distance and probably results in close scoring either way. Wouldn’t be surprised with whoever the winner is.
Bugner would try to peck and poke his way to a decision. George roughs him up instead and gets a decision.