I bought a rebuilt from a local suppilier a few years ago. Got out the spray can paint stripper to remove the rebuilder's black paint. Cleaned up pretty nice, as original with a warranty for about $75.00. Another method I used for the alternator is to get the correct case & clean it up as new. Buy a rebuilt unit & install the guts in the old case. Works very well. Have not tried this with a wiper motor but I don't think it would be too hard.