The “official” method of cleaning that commutator is with emery cloth, so sandpaper will do. I might wrap the paper around a popsicle stick to give it a little flat backing. Then use a fine screwdriver or point to clear out any debris between the contacts.
When glueing plastics, I have found that drilling small pilot holes which the glue can flow into and grab can add strength. Or rub epoxy or glue into a piece of shirt and reinforce the glue with the saturated cloth, much like fiberglass is done.
I think you can pull off the repair.
Wear all the protective gear, and as an extra precaution I might make sure the area is clear of dry leaves in case it throws sparks.