There are 2 versions of the shut-off valve, also called the service valve.
Most have a built in pressure relief valve sticking out opposite of the
regulator connection.
Late tanks have a separate relief valve screwed into the tank itself.
Both valves are available but the older type is more expensive.

Here is a link to a full replacement valve kit for all but the late
tanks. Since you have a 91 it might not be for you.

https://www.ebay.com/itm/Propane-Cylinder-Tank-Valve-Vanagon-Westfalia-Service-Fill-Bleeder-Regulator-LPG/184341023650?hash=item2aeb94cba2:g:FC4AAOSw4Lle9NHP

Mark

Steven Johnson wrote:
> Hey Folks,
>
> Anybody?  Venders?   I can't seem to locate the propane shut-off valve
> from anywhere.
>
> Any leads?
>
> Thanks,
>
> Steven
> 91 Westy