It is possible to install, as I did on my '90 westy,
a gas pressure gauge.
I happen to see one made for that purpose
in a camping supply store.
The gauge is called "Gaslow". Installed it between
the shut-off valve and the gas regulator.
Had to move the regulator over a bit to the left.
The gauge does give me a indication when
it's time to refill with propane.
I made marks on the scale for empty and full
levels, since the original scale is designed for
a bigger tank.
One additional benefit of the gauge is that
one can now tell if there is a leak in the
system when the shutoff valve is turned off.

I tried those stick on strips, but wasn't too
impressed with them.
Harald
'90 westy