There are a few of these I've found throughout the city. This was one, a shop on Vernon, you'd pass it by every day of the week if it weren't for the signage, handbill outside, even then hard to notice...
up a cramped stairwell & hall, a couple of adjacent rooms, the indifferent proprietor working in one, I peruse the museum. I say museum because very little is for sale, most is on display simply to be marveled at, photos shared below:
Everything from fossils, skulls, bones, antiquities, very little for sale (that's ok, very little of real value, but a curious room nonetheless...)