It warmed up enough so I could get the existing regulator off. It's a brand I have never heard of - a Fairview GB-630. This one is marginal with 100psig inlet pressure and 500K Btu outlet @30psig
I looked at the Marshall MEGR-6121-30 but that one may be the Rolls Royce of 30 psig regulators but only has an inlet pressure of 100psig. I also looked at the Marshall MEGR-130-30 which seems to be a better one for RV use with inlet pressure of 250psig (
https://www.marshallexcelsior.com/st...pressure-fixed ) and a million Btu output.
I'll be ordering this one, Marshall MEGR-130-30 along with a new 20" pigtail
BB & Carl, Thanks for pointing me in the right direction (and Carl, the 6121 may no longer be available)