I use to do a bit of part time tour guiding at an air museum that had a collection of airworthy WWII fighters, including an F4U Corsair. We had a few other guides who were ex fighter pilots, one of them, Clarry, flew F4Us in WWII. When I knew him, he was in his 70s, and always had a pipe, either clenched between his teeth or being fiddled with, tapped, loaded with tobacco, relit, etc. When the pipe wasn’t in his mouth, you can see that it had worn his teeth away. Anyway, he took great delight in demonstrating how to get into the F4U. Even in his 70s he could jump in with no trouble, up on to the wing, foot in the little door, other leg up and over the sill, and in the seat.