I know you prefer the first sculpt, Ben, but isn't it likely that it was just revised because it was so off-model? It is very Penguiny, while the revised sculpt resembles the stock art.
BTW, although scarce, the first Mxy sculpt can make a nice Golden-Age Mr. Mxyztplk...
WANTED: RM Robin & P. Parker heads; Batman "waffle" gloves; mint Wolfman tights; Knights', Merry Men, Conan, & Dale Arden swords; Lion Rock (pale) Dracula head;T1 GGoblin body (in good shape but can restring); POTA Soldier Ape minty bandolier; yellow bridle & stirrups; POTA Stallion complete set of tack; Fighting Furies Spanish & Buccaneer outfits & boxed Hook.