UK Specialists in Rewinds, rewind armatures, field coils , commutators, bearings, motor capacitors, carbon brushes, anti-tracking varnishes, electric motor cleaning solutions, regulators, solenoids , solder
www.robsonandfrancisrewinds.co.uk
They should be able to rebuild it for you. You'll then have a new unit rather than a S/H unit of unknown condition.
I am unable to reply to your conversation because it's locked. The part you require is a clutch actuator, part no. 6N0142063A (or B or D), available from VW or Audi. I wouldn't buy a secondhand example - it may not be better than the one you have and is really a consumable item. If the unit is leaking oil, you need a new unit. If the potentiometer has failed, send the unit to Mankmil on a2-freun.de; he will replace the potentiometer with a Hall effect sensor which is a non-wearing part. This is cheaper than buying a new unit. He speaks English.