One of my commenters noted that Gary's daughter, Elise Gygax, appeared in another TSR ad back in the 70s, this time for Gamma World. The ad apparently appeared only in the UK in an issue of White Dwarf magazine. Consequently, I'd never seen it myself, but reader Jarl Frå Oslo did and he kindly scanned the image, which I reproduce here:
The good Jarl also has a blog, Demons & Dragons, which I am happy to add to my links below. A pity it's in Polish, a language my great grandparents more or less abandoned after immigrating to the United States almost 100 years ago, so I can't read a word of it.