John,
You have the Sweetest Whispers. They are stepped attenuators.
The first question is do you have a FP III or FP 2 (you have posted in General rather than FP III or Legacy)?
Next, why do you want to replace them?
If all you need is continuous, not that it it gets too loud with just a few clicks, then you can just replace them with mono audio taper pots. You need a 50-100k for the FP 2 and a 15-20k for the FP III.