Depends, Brewster was a hard hitter with a good chin and was accustomed to come from behind KO wins. He was also at times a horrendous plodder and has been outboxed by men that shouldn't even have been in the ring with him. I say Wilder wins, because Wilder has shown he can move for 12 rounds. The danger would always be there that a Brewster left hook detonates Wilder though.
If Brewster shows up he'd spank Wilder down. Wlad threw the kitchen sink at him and he kept coming. I can't see Wilder stopping him unless he catches him absolutely square on the button. With his accuracy that seems unlikely.
If Molina can catch Wilder with that hook than I'm sure Brewster would probably find his. Wilder is too flawed technically. Eventually Brewster would catch him.
