Picked these up the other day, but I know squat about farm wrenches.

Top is marked Massey-Harris Z-43 w/Canada on reverse side
Middle marked <M-H> w/ M555 on reverse side.
Bottom I haven't found anything yet, needs soaked.

These worth keeping/trading or better sent down the road?

Massey Harris has a pretty good following.   Great tractors in their day, some time around 1960 they became Massey-Ferguson.   Ag wrenches are pretty popular among the MVWCA people.