I would imagine most people buy a plain knob to add to a choke or heater cable I don't know of anyone reproducing the original. Your hoses are just hooked directly to your heater because the valve is missing if you are looking to make it correct you need to run it through the Ranco valve as shown. The bad news is the Ranco valves and repro knobs are available but the other pieces are not reproduced so Swap Meet or eBay is your option. This valve assembly is and early attempt at temperature regulation in the cab not just on/off. When I have sold heaters in the past I include all these various little parts because of the difficulty in finding them.
