Here is a set made from Baldwin(?) organ pedals and and a Vern Jones MK-2 MIDI interface. I didn’t want to spend much time making an enclosure for them because I had the intention of selling them, and figured the new owner would provide an enclosure if he wanted one.
The pedals were wired correctly for the most part, but like many sets of pedals and MIDI interfaces, it required two different common (ground) wires for the pedals. I decided to bypass the electronic components on the IC board and go for a more straightforward wiring. The mechanism for triggering notes on these pedals were different than the Hammond pedals I was used to. Attached to each pedal was a small metal hook, much like the number 7. This hook is pushed upward into a small spring contact which is pushed up against a “U” shaped contact which triggers the note. I was able to wire the common to each spring contact, and the note’s contact to the “U” shaped contact.
13-note pedal sets are sometimes divided into two sets of notes, each with its own common wire. These pedals had one common wire for the first 8 notes and another common wire for the other 5. I had to brake the contact on the IC board so the common wire from the first 8 notes was not connected to the second set of notes by scratching off the solder on the IC board. Connecting both common wires together makes none of the notes sound.
I go into more detail about Vern Jones and the interface in this thread.