Here are two cultivator wrenches made by the J. D. Tower Company in Mendota, Illinois, beginning about 1872. The wrenches are 5 3/4" wide and 8' high. They are reasonably crude cast iron wrenches. One has a blobbed "O" boss, the other has a clear "O" boss. They are slightly different. I don't know why.
A note on farm wrenches. More than 50% of Americans lived on farms until about 1924. This may account for both the large number of still extant farm wrenches and correspondingly large numbers of farm wrench collectors and farm wrench auctions.
Note: this is a corrected entry, thanks to advice of Tool Talk friends!