Here’s an idea for a ring modulator. I used a 3080 for the balanced modulator from the Ring-Modu-Matic. I used an envelope, from the Meatball,  to control the carrier frequency.

This is untested. The controlling the FET to turn on the carrier is going to be a challenge.

There were a few mistakes in the last version of this. Here’s an updated schematic and PCB.