The other regulator, including: Lo guage, attachment nipple, and barbed check valve came as a set, as the Foxx "Add-A-Reg" in their catalogue.
Yes, I am aware that it is lefty-tighty, rightey-loosey in this case.
The vice grips did some chewing, so I decided to just take it to Air-Liquide, where I am a current customer, and see if they will fix it for me. I also discovered that the nipple is stardard (right handed thread), so I will need some kind of adapter to take it from that to LHT.
I'm afraid to bring the blowtorch anywhere near the body of the reg, since it is a sensative measuring device.