To use that growler properly you also need a worn out hacksaw blade. Try to find some old mechanic who works on starters and generators, he'll have one.
Along with the growler you need the commutator lathe. After smoothing the commutator, it had a cutting wheel to regroove the commutator. When I turned wrenches in the early seventies, the shop I was at rebuilt our own starters, alternators, generators, steering boxes and carbs. Back then our labor was still less than the rebuild shops, and the boss said our quality was higher. His theory was that if we couldn't rebuild it, to replace with new parts.
