How about a Roger Mayer Red Lion Wah upgrade kit. It fit all common Wah pedals and the upgrade ist done in 5 minutes.
I used to play mine for several years until it accidentally broke.
Here's a clip of the Roger Mayer Red Lion Kit:
Wah sound starts at 1:44
http://www.box.net/shared/krams2yl9s
"A lot of people in the industry want to blame downloading for the state of the business. But I think if most music wasn't shit to begin with people wouldn't be downloading it for free," - Corey Taylor (Slipknot)