Is there anyway to link two MF-101 so I can get a stereo filter?
Yes. You’ll need a TRS to TS and TS cable. I don’t remember what they are called but it’s a Y-shaped cable that has a TRS cable that terminates into two TS plugs. The TRS goes from the instrument and each TS plug goes to the inputs of each MF-101. Hope this helps! 
Insert cable? That would just split a mono signal into the two separate Moog Filters. I want to be able to turn the Cutoff or Res on one filter and have the other change as well.
then you need a control module where you have multiples to split it out, and an external control source.. the mixer on the control module can do this…
Yowza! I must have had the “Notify me when a reply is posted” off that time as I never saw the rest of that thread. 
Please delete this thread if possible.