John
I am sure wsaak is correct on the pedal. On my #16 binder it is used to tip the beaters (sails) forward or backwards. By releasing the notch with the foot pedal you then push the beaters forward or backwards with the lever that you adjust the height of the beaters with.
On your spanner (WRENCH) that is a new one for my list. I have #4105 and 4106 but not 4103. I wonder if there is a 4104. 4105 and 4106 can either have J I Case Plow Works or on the handle. Having gone all through my lists I wonder if I have miss read the number. Is what I thought a 3 in fact a 5?
Alan