I recently got a spare starter for my racecar and it needed some parts when I took it apart to clean it up.
In my early life I owned a starter and alternator rebuilding company. So I had a good idea of what I was doing.
The Bosch company makes great electronics and they are pretty easy to rebuild.
I found this company online that had all the parts I needed to rebuild my starter.

www.aspwholesale.com/index.php?

Prices seemed fair and they shipped right away. You will need to know what your unit number is but it should be stamped on the case.

There are plenty of tutorials online With video so anybody with some minor skills can do this.

Thanks for the link!