Vortex Sound Research

As the title says, the filter knob on my little phatty is broken. It doesn't stop at the max and min like it should, just goes around 360 degrees, and the light indicator (and filter) aren't affected.

The position changes when changing patches so I know for a fact it's the knob (also the fact that it doesn't feel right and moves all the way around while the other 3 don't)

I know the Little Phatty is no longer produced. Can I still send it in to Moog for repairs? I've had it since late 2013 so if there was any kind of warranty, it's probably expired now. Not sure where to go as I have no experience repairing synthesizers.

Thanks in advance to anyone willing to point me in the right direction here.