Ford Truck Enthusiasts Forums - What LPG/Propane Conversion Do I Have?

I just purchased (3rd owner) a 1982 Ford Class C motorhome built on a Ford E350 cutaway chassis with 58K miles. The engine is the 4bbl carburated 460 big block with a dual fuel LPG conversion. The conversion has large tanks on either side of the chassis and appears to be a professional if not factory installation in the engine compartment. The fuel gauge and dash mounted propane-to-gas switch is mounted in a clean but DIY fashion. There are no identifying markings on the readily visible components. The propane regulator/converter doesnt have the same ports that I see on the Impco Model E units on eBay. Specifically, there is an electrical plug with multiple wires on the left side of the unit going into a recepticle that is cast into the body of the unit. The rear of the unit has a roughly 1.5 inch long cast domed projection with the output line to the carb/mixer coming out of the center top of the dome. None of the regulators/converters I have been able to locate have electrical connections. The embossing on the back of the regulator is hard to make out observing it with a mirror, but it seems to be an oval and I could easily convince myself that it was a Ford logo. Can anyone help identify the manufacturer of this conversion based on this limited information? I know Ford supplied factory dual fuel units, but I have been unable the locate any manuals or other info to suggest that they so equipped the 460 engine. Any help would be greatly appreciated.