The first person I thought of is Cameron Kessinger, from So. California area.
Hasn't been active in a few years though. Don't know if he sold his stuff, but he used to have lots of "paper" & other casino memorabilia.

Also, there are a few dealers at the annual convention that have this type of material.
I'll look through the convention booklet from last June and see if I recall any particular dealers of this material.