About the thumb wheel being "distinctive", it isn't necessarily so. I have recently seen a Whitman & Barnes WH monkey wrench with the same thumb wheel. A 6.25 - inch Sterling WH wrench, made in Sterling, Ohio has the same thumb wheel. The 7-inch Johnstone Harvester Co. wrench made by Vandegrift of Shelbyville, Indiana has a similar wheel as do the Nos. 30 and 31 WH farm wrenches made by that company. The heavy grooving on the thumb wheels of these wrenches was intended to facilitate wrench adjustments being made by frozen fingers in winter time.