Gleason! He was into anything modern. He was using a ballpoint by C. 1950. If you remember that large color SP I discovered and sold, that was signed in what appeared early fiber tip or Sharpie. That was 1962/63.
They weren't mass market disposables back then except for Sharpies, right? That's what made them so popular. And a big use of Sharpies as I recall was to write your kid's name on their clothes when they went to camp!
Back then people rarely carried around photos to be signed unless they got ahold of a promo photo, or with their own pens. And almost all were personalized.
McQueen carried a felt tip in the later 1960s, but always blue that I've seen. I don't recall seeing any unpersonalized SPs but a few may exist.