Help piece together a burner

I got a burner for practically nothing, but I had to go out and get a regulator for it. I also went ahead and got an extension hose. In looking at it closer, and doing some Googling, I think I need an orifice adapter. I also fear there is something else I am missing, but do not know what. See pic. What holds that plate (which I believe is some type of air intake/regulator) in place? Any help or close up pics of how all this connects would be greatly appreciated.

Thanks,
Dave

I may be wrong but that looks like an adjuster for the fuel/air mixture. Propane should flow through the center. Does the regulator not connect there? It looks threaded from here.

On my Blichmann burner, which is very roughly similar in design to what you've got pictured, there's a spring that sits between the "nipple" on the burner end of supply hose which screws into the burner itself and the little plate bit. It catches on the wide hex part of the nipple and holds the plate flush with the burner.

I think that nipple is what I am missing. It looks like it needs to be Male/Male adapter about 1/4" on one side and 3/8" on the other.... not sure I understand the spring though.

The spring holds tension on the air intake plate so it stays where you put it. The nipple that threads in needs to have a really small hole in it to shoot propane in. I suppose you could fill a normal nipple with JB weld and drill it out.

A standard LP orifice should screw in and hold the air adjuster.