I found this small, 6 7/8", Vandegrift farm equipment wrench in the jumble of a country junk shop in rural Maryland. It's stamped JHCO, which lies within a rectangular border. The wrench is so small, the Pat. data are printed on two sides. The upper jaw is stamped "18", and the inside of the handle has "15" embossed near the main body of the wrench. This is the only Johnstone Harvester wrench of this kind I have seen.
Are these more common to the west of here (Eastern PA)?