As if disassembling and cleaning all linear pots  of this ARP 2600 is not enough to deal with, several levers were also broken and missing, together with the caps.

Amadeus from drucke3d.de made a 3D CAD model from the parts of a broken slider pot, evaluated the best production method and had some new levers sintered for me.
The caps could be made on a typical 3D printer.

All parts cleaned, waiting for assembly

Eveything lubricated and put back together

Good sliding action and no dropouts anymore. Mission accomplished 🙂