the sk code was "k". for example, k or 1234k marked on the tool would signify it as being sk made.
if i recall correctly, short, standard and long wrenches, speed handles, palm ratchets flare nut wrenches were the most of it. probably missing a few.
i just pulled out a cman 2010-2011 catalog from my stash. absolutely crazy how many quality tools were available. from craftsman in that catalog as well as tools from wiha, wera, fluke, dewalt, hobart, lincoln, knipex, sk, channelock etc.