Great article, Deve.
Until this afternoon, it could have applied to me...
as I was given an old "rusty" 12v blower motor from a '70's Bronco.
I test ran it before cutting off the mounting shroud, dismantled and thoroughly cleaned/serviced it, and attempted to put it back together.
But when taking it apart the bronze bushings came out with the armature.
Unless there is some sort of repair trick, I doubt the bushings can be put back into their sockets within the shell case -- there are little steel pawls that keep the bushings in place.
Too bad, as the modified motor casing might just have fit the heater core.
So if no-go, then it will be to my alternate plan: finding a more elegant way of dropping the voltage without the use of a power resistor.
Here's the heater assembly I'm up against:
http://s525.photobucket.com/user/my_pics48/slideshow/3100%20Truck