Bob,
This doesn't precisely answer your questions, but I'm thinking Hogan played in a bunch of majors before his first success in the PGA.
Hogan won with 276 at Riviera, which set an Open scoring record. I'm thinking over-par won at Merion (287?), and slightly under par (283?) won at Oakmont. He conquered Oakland Hills in the final round with 67, but was over par for the 72 holes. (287?)
From what I have read, Olympic in '55 was a real beast comparable to the Oakland Hills setup. You are right that Hogan won at some real tough setups.