Denny, my 52 3100 came with a hand crank under the seat. I do not know if it is original to the truck.
The thing which stands out to me is that the end which goes in the end of the crankshaft is not cylindrical like the rest of the shaft, but rather, it is significantly flattened in the same plane as the lug pin. I was guessing that this configuration was to aid in throwing the crank out of the hole upon engine start up before you got wrapped up in your work, if you know what I mean.
Carl
