Well, I looking around at some things. What struck me is that they are flat-sided like carpenter's pencils. So I was looking for drafting or art markers because someone might use them on an inclined desk. Apparently people aren't in the habit of selling old markers--not much luck. However, looking up highlighters did show some things that looked intriguing.
Staedtler Textsurfer Classic Highlighter:
The "Classic" suggests it's been around awhile.
The other prop that has a sort of angled cap kind of looks like these Stabilo Boss Highlighters:
The "Original" also suggests they've been around for years.
So those are some suggestions to look into for vintage versions.