Fixing potentiometer tracks on a ribbon
The part that's worn - may just be a 'jumper' -- the resistance may not matter as the slider shorts across. 

But I think displacing the element sideways is probably your best bet. 

The polyimide film is screen printed with a specific type of resistive ink, which is then cured in an oven. Not rocket science but not very practical for one piece unless you're in the business.