many parts for the classic Penn reels are available on Ebay. You could pick up a "beater" reel to use for parts. Also, you can try your local flea market. I picked up a sweet Penn 712 greenie earlier this year for around 30.00 at the Taunton Flea . It works great. Here is a link with some Penn history in it:
http://www.tattoostackle.com/americanclassic704.php