I previously repaired a broken terminal on one of these motors. It was broken off down in the plastic. After getting the motor apart, I found an old on/off switch which had little flat terminals the same size and shape of the motor terminal. I broke the switch open and stole one of its terminals, used it to replace the broken-off motor terminal. It did not have a locking tang, so after installing and soldering it inside, I gave the new terminal a quarter-turn twist on the outside to lock it in place. When I was trying to figure out how to get the motor apart, I decided to use a hobby motor gear puller, and then slide out the armature with the end bell still on it. That worked OK, next time I will try the method above with the holding pins.
Now it looks like I will be doing more motor work. We are purchasing new motors to replace two that burned out this week, and will get the motor-protecting cabling. The motor that had been previously repaired is one that burned, it is starting to look a little rough due to all the handling. I might experiment on this one, just to see if I can make a fault-protected practice motor. The companies that make polyswitch fuses make some for low voltage motors, the leaded ones are about the size of the motor's original inductor.
For some background, here is one mfg's site
http://www.circuitprotection.com/app...brushdcmotor=1
I have not picked a fuse yet, probably go for one with about a 30V rating, a hold current in the 3 to 5 amp range, trip current in the 5 to 10 amp range, trip time in the 1 to 2 second range. But these are expensive components, I may have to spend as much as 50 cents. If I can make it un-burnable, I will update this.