Let me tell you a little story incase it's a distributor.
I bought a forage wagon from a guy one time. He had a restored Ferguson 30 sitting there. He said it had belonged to his dad. He said that years ago they were hauling hay with it. They pulled a load up with it and the battery gave out. He said they ran to town and got a new one, put it in and every since then it wouldn't start with the starter. It'd crank over, but not start. He said if you pulled it two feet it would start.
He said they gave up messing with it and parked it for a lot of years. His son got old enough and wanted to restore it. He discovered that years ago when they put that new battery in it, they hooked it up negative ground instead of positive ground like it had been and was supposed to be. He said the boy put another new battery in it, hooked it up positive ground and it started just like it should.