Measure the pot in all dimensions. Firstly, measure the bush thread's width. Then check the maximum depth available to fit a new pot (getting vintage parts from Panasonic is harder than major dental surgery). Check the shaft height and width, i.e. that your knob will fit the new pot.
I am supposed to be working on some SL110s soon. If they need new pots (they usually do) I'll let you know of a replacement. It's an easy job btw. Mouser / Allied / Digi-key will all sell pots that should work - just make sure you don't order the wrong one.
Please note that this account is dormant for the time being. I apologise to all that have sent PMs - there are just not enough hours in the day!