Regarding your starter and its chewed up teeth; you'll need to verify whether you have a 12v starter or a 6v starter. You'll also need to verify the number of teeth on the flywheel.

12v starters need to be paired with flywheels built for 12v and 6v starters with 6v flywheels.

The number of teeth on each flywheel is different and the cut of the gear teeth on the starters is different.

I can't remember which is which but do a quick search on this forum to find numerous discussions on the subject and how many teeth each flywheel has.

Getting them mixed up will cause the grinding you describe.

1950 Chevrolet 3100 (Ol' Roy)

1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1964 Ford Galaxie 500 coupe |1966 Ford Mustang (Little Red) | 1969 Pontiac GTO (The Dishpit) I 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)