Phantom 301

[shelfstacker]

I've just bought an early Phantom 301 that hasn't ever been used but the mast track adjustment pedal doesn't work. Possibly that's why the dealer never sold the board?
There is no resistance in the pedal itself and there is no contact between the underside of the pedal and the rotating aluminium strip that should be pushed down to allow the mast base to slide to a new position. (This is with the pedal in both its forward and backward positions). It looks like a spring and the pin to mount it are missing from the base of the pedal? Is there anywhere I can see a drawing of the parts of the pedal as they should be so I can try to get a replacement?
Ta.