I think you're right about 'Pinup' style being reminiscent of 40's-50's style girly pics/paintings (i.e. aircraft noses). I personally love that look and can't seem to nail the PP technique.
I seem to think it has something to do with really raising the exposure and brightness, and kind of flat lighting. Really blasting the subject with light. But I could be wrong.
Roger was doing a "modern retro pinup" look combining the two time eras and styles for something unique.
A quick search on the Human Form section turned up one great thread from a Pinup Workshop. There's some great examples in
HERE
(No Nudity in this one)
I, too am curious about the PP routine behind this look though.