Update! Went back this morning and looked at the 3 machines. Thank you everyone for the information and advice.
I've been thinking that the 15 clone price was way too high. It's a pretty machine, but for that kind of money, I'd expect it to have all the attachments, completely cleaned, no veneer starting to come off the table, an espresso machine, etc., etc., etc. lol I still wouldn't pay that price, though. I may keep my eye on it just to see if the price comes down, a lot. Anyway, my life isn't over because I didn't get it.
Buuuuttt, I did bring home the 66. Yes, it is a 66 (I took a list of the numbers from ismacs with me to make sure). She just needs to be cleaned up. I think I can easily take the paint splatters off, (after I watch the videos linked on this board and reading again the thread by Glenn). Wires all look good, no fraying. And for $20, it's a good project to start with.
I'll try and post pictures of the 66, but also the Winthrop and the 27 that are still for sale.
Was it me who said "I never thought about having more than one machine?" I'm going to eat those words.