My experience with this is mostly in New York City and San Francisco. In both places, stores in past years at the edges of the city, generally in modest districts, had the best selections of old bottles. In New York, it was almost always ND and generally OT or OG. When I go back to the same places, you can still find bottles sometimes, but not as much as before. In SF, the same applies basically but there was more variety, e.g., I've seen 70's Dickel, 60's Harper, Beam decanters, brands that were unique to the area sold by bottlers like Frank-Lin, and 70's Heaven Hill (two bottles with a corn-heavy old-timey taste). Persistence often pays off though, and I find this is so almost anywhere.

Gary