This is a design by King of Random with a few key tweaks.
Parts List:
1x3/4 Stainless Steel Reducer
3/4x6 Black Iron Pipe Nipple
1 1/4x3/4 Galvanized or Black Iron Reducer - drill and tap holes for set screws
1/4 Brass Plug - drill #57 hole (1.1 mm)
1/4 Black Iron Coupler
1/4 Black Iron Street Elbow
1/4x10 Black Iron Pipe Nipple
1/4 FIPT x 3/8 Male Flare Needle Valve - very hard to find, let me know if you find another source for these
I sell these burners for 80 each. Or you can buy the parts and the assembly and machining yourself for 60. I also sell a connection kit for 60 that comes with a 30 psi regulator, 6' of propane hose, and the brass fittings to connect the burner to the propane tank.
You can find forges, burners, and and parts on my website Rushfireforge.com