Dwight, A lot of H and M Farmalls have this problem, including my H. The starter gear hits and locks up against the ring gear without meshing properly. At first the problem seems to be electrical, but I am betting it is not.
Put the tractor in 5th gear with clutch engaged (ignition switch OFF) and then rock the back wheels as hard as you can and the gears should unlock. You might hear a "click" as the starter gear comes free.
Another method is to loosen the starter mounting bolts slowly until you hear the "click", then retighten the bolts.
If I start my H by not pressing on the starter button hard enuf the starter often gives kind of a stutter and I get the lockup. If I press hard I rarely have the problem.
LA in WI