MF240 starting trouble

Need help figuring this one out. I have been having trouble with my MF 240 starting on and off most of the spring/summer. At first, I thought the problem was due to a weak battery as jumping of with running truck would start it and the battery was very old. I bought a new battery, but this did not help at all. Then I thought that it was the starter. I pulled the starter and took it too a starter/alternator shop. It was placed on the bench and he "tested it" and said it looked good. I should check the switches and connections. However as soon as it put it back on the tractor it started back up. I chalked it up to connections at the starter. It has worked for about a month, but turned over a little slower than you would think a new battery would.

Now will not start. Battery at 12.45V at battery and starter. Jumping at battery no difference. Will not turn over at all. If i connect running truck with jumper cables directly to post at starter solenoid and starter ground, I hear rapid clicking when turning the start switch. If i try to start at starter with screwdriver across solenoid, it barely growls for a second like trying to turn over. (Tractor in neutral)

Any ideas appreciated,
Thanks.

PS.
I don't know if the starter is bad, I have a weak ground, or bad switch.

It can test good on a bench, but you really need to take it apart. Worn bushings/bearings could cause the armature to drag. With the starter out you can try to turn the engine over by prying on the teeth on the ring gear to see how hard the engine turns.

Check your battery ground cable, especially the end that connects to the frame. If it connects to metal other than frame, such as fender or battery box, move the connection to the main frame as close to starter as possible.

If any question about cable replace it.

UPDATE:
I started thinking it was the ignition switch, as gradually as I was testing, the gauge lights stopped coming on. I replaced the ignition switch with new, but it made no difference. I looked at the fuses (which look good) and sprayed electrical contact cleaner on the holders, but it made not difference. I have checked the ground cable, it looks good. Using meter I get 12.5V from + battery post to ground wire bolt. I took the starter off again. With a screwdriver, I can push against the gears inside the tractor to turn them, but can't turn them with my finger. When I use jumper cables on the starter, I can get the solenoid to fire and the starter to rev up. I took the starter to advance auto, but they couldn't find a part number for it that would work on their testing machine.
Questions: 1) How hard should it be to turn the gear on the tractor that the starter turns?
2) Is there any started problem that would cause the gauges not to light up?
Any advice greatly appreciated.