I'm new to the site, but hope I can offer some assistance. I've already received great info from several members.
I ran into similar problems trying to find a Ranco valve too.
My old heater was missing parts and a valve. After disassembling it and locating some parts, I found the valve search to be the most difficult. I checked with the major suppliers, craigslist, googled, and ebay. I found several varieties on ebay, and contacted the sellers to inquire if they had the particular valve I was looking for - with no luck.
After speaking to Jim Carter's customer service I asked them if they couldn't supply one would they know someone who might. They suggested Tom Myer's Auto parts, in Miami, OK (918) 542-3871. Tom was able to supply a valve, control rod, and respective brackets.
