Is there a rebuild kit for the Heater Control Valve for an Advance Design Truck? It would be for the Deluxe Heater.

Need a rubber gasket, round looking thing, sorta, kinda? That goes into the valve.

The shaft that goes into the tube has a stainless pluger on it, is it suppose to have a rubber o-ring too?

Need schematics to this thing.

Help!