Here in DC/MD/VA, seems like all I see for the most part are 70s Williams games... one of the biggest distributors of pins in our area, was extremely frugal, so my theory is that he wasn't going to pop on any old Gottlieb, although I do remember seeing more and more of them in the mid 70s.
The Gottliebs that he routed seemed to be out on location forever.... I remember seeing a Royal Guard and a Sing Along at a department store that he serviced all the way up to the late 70s. 10+ years in the field back then was pretty rare, at least in our neck of the woods. Bally 60s games - very rarely see them either... I'd love to see some stats on the distribution of Bally EMs from the 60s... I don't remember seeing any Bally EMs from that time period... weird.
Interesting that Snow Queen/Snow Derby was discussed; I've only seen 1 for sale here since I've been in the hobby, starting way back in 1988. And woodrails - most of my leads for those come out of Western Maryland/West VA areas.