I just had a failure on a recently purchased 1920 Cadillac. The starter bendix gear has a hollow shaft that should be lubricated with transmission oil. Mine ran dry.
The bendix stuck in the flywheel and the engine spun the armature throwing off wiring. I am having to rewind it, and new bushings in the bendix.
LESSON!: go over your lubrication chart and oil/grease everything! Do not assume the previous owner did proper maintenance!