Hi Matt,
Nice gun! I recognize it from Gallenson's, no? Did you happen to notice a 625 Mountain gun in 45 Colt sitting near it in the case? It also was in new condition with a fantastically smooth action, and very tight. According to the guys in the store, the 66 you bought and the 625MG both were from the same owner (now deceased) -- the 625MG has the same green fiber optic sight and Miculek grips, so I would bet a paycheck that neither gun came from the factory that way. Regardless, they were both very nice pieces.
I went in there on my lunch break earlier this week and picked up a like-new 686 Plus 7-shot with 2.5" barrel, $345 out the door. Sometimes good stuff shows up there...
-Dan