The screen was revised in 1983 for 2nd edition
GW, with the code GWAC1. Perhaps that is the second stock number?
http://index.rpg.net/display-entry.phtml?mainid=7860
The Gamma World Rules Supplement is for 3rd edition. That set was missing a bunch of rules, so they had a mail-in you could get for free. I had a copy, which I sold a long while back with my 3E set. It was a coverless booklet with some recycled Star Frontiers artwork of a Dralasite on the cover.
Here it is, including a cover shot:
http://index.rpg.net/display-entry.phtml?mainid=5810
However, that page gives it a stock number: 7110XXX0501
So, the page you quoted above could be referring to something else.
Zenopus Archives
website &
blog: Exploring the Underworld of Holmes Basic D&D.
Holmes Ref: Reference Sheets for Holmes Basic Referees, also compatible with OD&D plus the Greyhawk supplement
