Just a note, if it seems to be a Kusan, look at the roof. It may be an AMT too, but AMT has a hump on the roof.
You can possibly have that one rewound. Checking out what is wrong is also a good way to learn more, even if you go with a replacement. (Maybe give Frank T. at Timco a call and see if there are adapter plates for a Pittman or other motor..? I do see those old ones on the Bay at times though)
If the timing of the brushes is right, you may not have to take it apart to know whats up; an ohm reading off of each of the motor poles might be possible at the brushes...? (each section should be equal ohm measured alone, no continuty to the shaft. plate unable to shift on the shaft. Gaps clean of brush dust. That is all there is to a motor...electromagnets and timing which pulls when)
