I would not try to clean up and reinstall the old motor as this project is
too time consuming to want to do again (you will kick yourself even if this
fix lasts a year).  You have two options.
One is new fan from me for $95.
Other is find a known good fan from a Rabbit (81-84) in a junkyard and use
this one.  I would recommend getting the new one from me, but I understand
money being tight so I give you the other option.

Hope this helps,
Ken Wilford
http://www.vanagain.com
John 3:16
Phone: (856)-765-1583
Shop:   (856)-327-0027
Fax:     (856)-327-2242