Honestly, I thought of the first one, one day and thought it was complete genius. So I tried to do more, the second one was not bad, but the rest were difficult ... so I, stopped. But the first one, though. That's why you're here.
Namor, The Sub-Mariner = Leonard Nimoy
Tony Stark, Iron Man = Hugh Hefner
Steve Rogers, Captain America = Michael Douglas
This casting would be easier if all the actors were in their prime so I could see it but at this point I'm just low-balling it. It was just for fun. In fact, Douglas could have been [Ant-Man](movie:9048) Hank Pym, which he is (older) in the new one because it's not centered around him.
Bruce Banner, The Hulk = Michael Caine
Sorry for wasting your time . . . -Sam . . .