On Thu, 23 Apr 2009 10:12:49 -0700 (PDT), wrote:

3. Copper Contact. This moves to the right and toward the graphite
contact on the left end of the Carbon Pile when the pedal is
depressed.

I would try adding some (conducting) padding at the centre of the bronze spring
(around the "3" area) to make contact with the carbon. Is it possible a
copper/brass disc is missing around there?

--
Geo