I was thinking of buying a rotary switch then fit it in place of this old -now useless- potentiometer
I disassembled the old, french potentiometer. It has a long shaft driving a small copper plate -which is supported by a spring- into rotatory movement passing it over a long, coiled wire. The coil run in 10 plastic compartments. The coil is continous between compartments from below. This design has great potential for my tranformation.
1- Raise the coil from each compartment & cut it. I have now 10 mini coils with almost zero ohm resistance for each.
2- Drill a small hole beneath each plastic compartment
3- Pass thin shielded wires through holes
4- Solder every wire to one mini coil
5- Draw wires back & push the mini coils into their compartments
6- Re-assemble the switch
You are done