Well, don't want to step on toes but there's too much assumption here. Chevy came with 12V in 55.2. I this offer a note. There are lots of reasons a starter "quits working". I would check a few other areas.
1. The battery and the battery cables
2. The starter solenoid or side terminal foot switch.
3. The ignition switch
4. Then a test on the bench with battery charger as a power supply
5. Then a visual and shaft movement test
6. Then an inside inspection, checking the bushings which have to be really bad to have a starter actually "quit" moving or growling or humming or intermittent or clicking
7. Then the brushes. Maybe you already see that brushes are worn down to nothing.
8. Then the commutator
9. Then check the motor for hydraulic lock or other.
I know you did not ask anything but where to get bushings and brushes, so probably you did all this checking. But without any symptom explanation other than "starter quit" and not knowing your expertise, thought I would mention a list for the archives. Helping is sometimes being sure the poster is not jumping a testing phase or is asking the right question. Like "why did my starter quite working".
9 G 13 is probably July 13, 1959
I agree with Shaffer, go to NAPA. Take old bushings and brushes, end caps, shafts, calipers........ Let them pull bushings/brushes until you find them. Don't care too much about part numbers if they fit/match.
