I don't know (I'm sure someone does though), but post 6 is/was in Cheyenne, Wyoming. I have green and brown square in circle mold chips from 1959-60 made by the Portland Card Co., if anyone is interested. These chips were painted on the edges with high gloss red and green paint, and some paint is on the face of each chip, although many are not too bad. I would sell these chips at $4 each plus $1 shipping for 1-2 and $.025 for each additional chip beyond 2.

I guess each post bought their own chips. There doesn't seem to be any uniformity in chip molds/manufacturers.

Michael Siskin