OK, as I posted previously we are selling the old serviceable rocker switches from our 1977 M20J. Up for sale first is a radio master switch.
This is Mooney part number 930023-013, and is a Klixon (now Sensata) 20TC2-BG-3. Technical information for this switch may be found here:
http://www.peerlesselectronics.com/store/products/20TC2%252dBG%252d3.html
It is a 3 amp switch/circuit breaker.
$49 plus shipping, this is a great price.
Edit, this has sold. Lasted less than eight hours. I'll have more rockers available soon. Thanks!