Maybe this will help you some.
20 LB Gas Bottle Holddown brackets 4733g6281 [4733g6281] - $36.95 : Out-of-Doors Mart!, More Airstream Parts on-line than anyone!
Turn the bottle you have around and screw in your regulator. The nut on the regulator fits inside the bottle connector and is left hand threads. The propane
system on the trailer you have wasn't designed for the newer type bottles with the OBD connector. If the lines restrict the connection you will have to go to the rv supply or propane
distributer to get everything squared away to fit the new bottle style. Make sure all your appliances are off and any flow valves closed before opening the gas bottle valve. The system should now be tested for leaks
. I urge you to take it to a profesional to have the system checked and have all appliances verfiyed working properly. I would not trust such an old regulator myself. Propane
missused can ruin your day or maybe your life if something goes wrong.
Theres usually a reason that the system wasn't properly hooked up when you bought your trailer. Could be something simple like just needing an updated OBD bottle or something really serious that needed attention that they couldn't afford to fix and just abandonded using the gas appliances. Right now everything is suspect.