Baer in about six rounds. I don't think he'd struggle to find Johansson, but he might be leary of the big right early on, as Johansson had a habit of standing men off as he pawed with his left, trying to time the overhand right. I see Baer having pause for thought, but not realistically losing. He's the tougher man, with the better chin & I don't think there's any dispute whatsoever his right hand is the bigger shot between the two. More worthy of Baer (at his best) would be the likes of Sharkey (also, on his best night), Patterson & Walcott.
Neither... but Baer's chin proves far superior. Johansson's movement and trickery might get him some early points, but Baer steps it up at some point and should prove too strong and powerful once that happens.
I always thought Ingo bombs Baer out. Far too quick and explosive. Baer's defence is honestly one of the worst I've ever seen at world level. Even guys like Lopez and Chacon were better in that regard, due to having a bit of mobility.