Re: Old "butt" Champions Mini's
If the box is Yellow then they are the Grenadier models I have 2 boxes one says Superheroes and the other says Super villains.
The Heroes have; Flare, Dove, Icestar, Marksman, Crusader, Mind Maid, Gargoyle, Starlet, Titian (the Iron man lookalike), Champion, and a do it yourself Hero, and Heroine.
The Super villain set has:Lady Blue, Mind Slayer, Utility, Jiant, Wreckage, Lazar, Wyvern, Ray, The Fox of Crime, King Cobra, Anklyosaur, and Sunburst.
All in 25 mm metal.
Date on the box lists it as 1984