Needless to say, the fan motor didn't work anymore, apparently because the windings were shorted out. I couldn't find a single motor shop that was interested in rebuilding the motor--it's just too much work, and there is no real money in it. I looked for a modern motor to replace it, but the 6V feature made that difficult too. The main problem, however, is that this motor sticks through the firewall and into the engine compartment. It's a very prominent feature, and anything other than the original would have look out of place.

So, I ended up rebuilding it myself. It wasn't too hard--it only took me about 8 or 10 tries to get it right. The trick was getting the windings orientated correctly between the rotor and the stator. I made this drawing to sort it all out.

In the end, the motor worked! I even got the fan to spin the right direction after a few tries. All in all, this was a great learning experience.