When I first saw this Russ Warner photo of Mr. McCune, I thought, "Oh no, this is one of those that somehow darkened over time." Then I slowed myself down and took a good long look, finally
coming to the conclusion that not only was it meant to be this way, but it's quite beautiful.
FWIW, Warner appears to have been the only photographer to get Bob to pose frontally nude.
Perhaps the fact that both were competitive bodybuilders had something to do with it.