Hi Jacek,
I'm more than happy to prepare my VX as best as possible prior to you doing what you need to do, removing the handbrake cover is not a problem. What other areas do you need covers removing and to gain good access too?
Personal until I see the size/shape of the potentiometer I will not be sure weather to drill a hole or mount on the bulkhead, etc. But I would be happy to just have this wired up and working and I can route the potentiometer wiring and mounting myself afterwards, leaving you more time to finish up or move onto the next guy. Anything to help make this as smooth and painless as possible.
Cheers,
Martyn