Hi Gloucestre,
Getting no output seems to me to imply a grounded hot wire.
It is possibly worth taking the pots out from the recess (away from the copper tape), and take out the jack, to see if that makes a difference (and hopefully some clear photos can be taken). Do not desolder them - just get the components out of the cavity.
Also - Do you have access to a multimeter? That can be used to check resistances (and shorts) in a circuit.