A friend who works for the local propane distributor just stopped by.  A
couple weeks ago I had him go through my Westy propane tank.  When I got
the bill I was rather astounded by the cost of the propane regulator.
 $28.12.  I asked if he could do more at that price.  Today, he told me,
"How many more do you want?"

So, if your regulator is passing gas through the vent and you need a
replacement, drop me a line. Marshall 290. $28.12 + the postage to get
it to you.

Note: the original regulator, Marshall 140 is no longer in production.
The 290 is the correct two stage replacement. It's about 1" (25mm)
longer than the 140, so you have to bend your plumbing just a bit.

Jim