I frankly do not recall how I heard of the NPL. I joined in November 1979. Around that time I did read The People's Almanac cover to cover (I never made it through The People's Almanac 2). I also read Borgmann's Language on Vacation about that time.
However I vividly recall reading an fine article in the January 1979 issue of Games, by WILLz, about the 1978 convention. In the November 1979 issue WILLz simply presented some of the games from the 1979 convention. No doubt that, and The Almanac and Borgmann, got me thinking I was missing something. So back to the January issue, which had Mangie's address . . .
First Issue: Oct 19791)
My nom is in fact a real pseudonym! It has been used off and on by Martin Gardner over the last 60 years. Martin gave me permission to use it, and I use it in honor of him. [. . .]
Martin has published poems, book reviews, articles, and the occasional letter to “Ask Marilyn” as George Groth, but no books.
Source: email from Geneac, quoting George Groth.