Blue Point YA7707 Test Box

I have a Blue Point instrument gauge tester like this one:

Blue Point Tool YA7707 Instrument Gauge Tester - tools - by owner -...

The 100K potentiometer died and I have been going round and round with Snap-On all morning trying to find someone who will claim this that I can get a replacement pot from. There is no vendor marking that I can see on the pot, the following is stamped on the back:

12637
20 9837

Anybody got a source for Blue Point parts? Thanks.