There were two different stock heater control valves. The early one has a bent rod that attaches to the cable. Later valves have a flat lever. Both ride in a slot cut in the brass valve body. Deep within the valve, there is a small o-ring; this is what leaks and is what you replace to fix leaks. Generally the valves are frozen up from disuse, so much penetrating oil is needed to disasssemble. The overhauls are pretty basic once the valve's apart; I recommend Viton o-rings for their temp resistence- and cable-operated valve! Safety shutoffs should be brass ball valves mounted somewhere accessible in the heater line, but outside the cockpit. All this is necessary because owners don't replace the two short heater hose sections under the dash, so they rupture at high speeds, scalding the drivers foot & blinding him with steam condensate on the windshield. Stock valves cannot be adjusted to both shut off completely and open fully, which is probably why you have two valves. The second valve is probably out of some other car.
