Unfortunately, no, not much. They made LOTS of those machines, from I believe the very late '60s (?) till '73 or so. There's no shortage of them that show up at flea markets, craigslist, ebay, etc.. So any collectors of vintage machines (a very niche collectible, mind you), have long since had no problem finding 66TRs floating around.
The late 1960s/early '70s saw a proliferation of metal detectors hitting the market. Now if you had a late '50s coin machine (verses a 2-box unit), you would have a vintage machine indeed, since things really hadn't taken off in that decade yet.
Can you remember what year you bought yours? I know they were made well into the early 1970s (as they appear in Whites ads all the way to '73 or so), but I'm not sure how early on they were introduced.
My first machine in about 1976, was a used Whites 66TR! Only 3 or 4 yrs. old at that time, but already a dinasour, even then!