Here's an ad from issue #59 (March 1982), though it -- and others in the same series -- appeared for many more issues to come.
Sir James, and I can't look at that figure and not recall my earliest days in the hobby.
After they lost the AD&D license, Grenadier produced minis for several others games I played a lot in my younger days: Traveller, Call of Cthulhu, and FASA's Star Trek. I know I owned boxed sets for the first two, but I never even saw the Trek minis that I can remember. Unlike the AD&D miniatures, I didn't actually use the Cthulhu or Traveller minis; I bought them primarily as "toys" that I could look at and stick on my bookshelf as knickknacks. That seems a bit odd in retrospect, but those were odd times, as future installments in this series will make even clearer.