It ain't a pedal but you could look into an attenuator:
I plan on buying one of these for my DeVille.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=010&item=200001950596&rd =1&sspagename=STRK%3AMEWA%3AIT&rd=1
Or just use your Fender Champ full blast at all times - that thing sounded pretty fucking sick.