I have recently bought a Flextone II with a floorboard on e-bay. I like the amp greatly, but found that the Wah Wah was faulty.
It needed a good clean anyway as there was a great deal of dust between the pedals and the top of the board. I had read somewhere that the pedals worked on optical inputs and wondered if the dust was clogging light path between the switches.
So, being an engineer, it had to come to pieces!
I found that actually the light switches looked fine, although I gave the graduated film strips a good clean with mild detergent and blew a few bits of fluff off them. The fault was in fact that over time the pedal bodies had distorted, through being stood on repeatedly I assume, and the small tang on the Wah pedal was not touching the on/off switch on the pcb which is mounted below it.
Once I straightened the body of the pedal out the tang / switch interface works fine and the newly cleaned opto strips are working a treat.
There is nothing much to the insides of the floorboard, so hopefully any reasonably competent person (who can use a screwdriver) can resolve this issue in the comfort of their own armchair as I did. I do however accept no responsibility for your individual level of incompetence, so if you mess it up don't call me.