Here are two obvious Reaper "not Fafhrd and Grey Mouser" figures, Fafnir of Kjord and Arran Rabin. Fafnir is in metal, the other in Bones plastic. Side by side, one can see that metal holds better detail, especially in the face, than bones plastic, not withstanding improvements in Bones II over Bones I. He's still worth picking up if you need a Mouser stand in for an RPG or skirmish game.
Leiber continually emphasized Grey Mouser's monochromatic apparel. On the page, it's fine, but on a figure it is hard to avoid a dull, boring look. However, put the Mouser against a grey stone background and I instantly see why the smaller man favored such an outfit. It's sword & sorcery urban camouflage.
Before my comic collecting days, but a little web research led me to this forgotten (better forgotten?) work from Wonder Woman's disco era costume days.