Bought a bunch of vintage/antique meat cleavers at our favorite flea market this summer, and among these was a 1/4" thick cast iron cleaver with a full-tang two-rivet oak handle. The blade is about the same size and shape as a brick (very slight curve) and it is marked near the handle "GM" in raised capital letters about 7/16" tall. I believe Griswold made meat cleavers way back in the day -- is this how they were marked if made by Griswold Manufacturing? Any info would be greatly appreciated. Thanks, Chris B