Found these TSR retailer poster pics on my hard drive this morning while doing website work. They were in a group of auctions somebody had back in 2014. Even back then, they sold for a pretty penny. They appear to date from 1978-9.

Enjoy!

4th Dimension poster
4th Dimension
Boot Hill poster
Boot Hill
Divine Right poster
Divine Right
Gamma World poster
Gamma World
Snits Revenge poster
Snit’s Revenge
AD&D PHB poster
AD&D Players Handbook