How do I know that Ancient Armor poster is popular?
About half of the TotA books that show up in the shop are missing their posters, a much higher rate than usual.
“The Ancients are a race of mysterious humans that once revelled in the glories of technology. Suddenly, inexplicably, they were wiped out. Their tools, their vehicles, their weapons, and other devices of interest can be found in the ruins of their former cities, buried in radioactive slag, or submerged under rerouted rivers and lakes. Treasures of the Ancients, a supplement for the GAMMA WORLD® game, details a plethora of these complex and valuable items.”

Treasures of the Ancients (GWA1)
1993 … Dale “Slade” Henson & Brom (cover) & Newton Ewell / Mark Nelson (interior art / +poster?) … 96 pages + tear-out color poster of powered armor suits … TSR 7517 … ISBN 1560765771
Gamma World 4th edition at our reference site
Treasures of the Ancients for sale in the shop
PDF and reprints available at DriveThruRPG
The Book

In the center is a two page art spread by Larry Elmore, familiar from module GW10 Epsilon Cyborgs. The art piece in Treasures of the Ancients is B&W and shows the other half missing from GW10’s cover.
The Poster


TSR was almost consistent when it came to organizing their maps. On this map, note there is a code on the border.
7517XXX0701 refers to the product number [Treasures of the Ancients = TSR 7517] and the part number (0701).
Maps were usually 700-series, starting with 0701, and consecutively from there if multiple maps were present.
Now that you know that, you can finally ID those lone TSR maps you find.
I wish other game companies did that too; would make my life a lot easier when IDing loose maps.