I can attest that the schematic works.
I just finished my pedal made out of a Behringer FC600 volume pedal and some bits and bobs.
In the end it probably cost me less than €100,00 in parts and a couple of hours of tinkering.

I found some info concerning the components on another forum.

Hi, I found this post while searching for info to build my own foot pedal (as the C100F goes for rediculous prices overhere also) Whilst searching the net, I found a PDF with the schematic. I'd think it would be the same for the remote (minus the on/off switch). No Idea how thrustworthy this is, but...