Nice finds on both radiant green ones. Also the one converted to 27s, before I forget.
I'm kind of wondering what freewheel/ rear gear cluster each one of the 26" wheel ones has since they're earlier than I have. I haven't really looked into this pre-sprint branded timeframe until recently.
The original post bike, the changeover of derailleur probaly also includes the wheels, if not the freewheel. Moving forward, I'd just go with some early collegiate rims. Maybe a schwinn derailleur. That's where I'd stay with the original style and just flip it.
Ymmv but imho, your main buyer is looking for an original, and even if it isn't, it still has that kind of look of 26" rims. There's other side to that as well that 27s and etc parts are a better deal for long term maintenance for someone going forward. Really I guess the best direction is the least cost.
I had a 64 coppertone one with a broken right lever and for me it was just more practical to break it down rather than take the lever off my collegiate. I was kinda going sell off the parts but playtime with another model interrupted that. It had an Atom freewheel, my 66 varsity has the sprint logo on the freewheel. Not sure about the collegiate freewheel branding but it's probaly sprint, being a 65 or 66.