Time to get this burner finished and out of the way for now.
The venturi, sitting in the background, needs to go down the tube from the jet end by a specific amount, so by using the thin depth reader on my digivern, that is what I did.

It was a nice 'grippy' fit down the tube, so it was tapped down with a hammer and soft drift until it got to the correct position. I got it to within 0.005" from where the drawing said, and because I have made the jet easily adjustable in/out, the perfect position for mixing can very easily be reached, a few seconds at most. It was loctited in position, as suggested in the build instructions.

The jet tube holder was then tapped into the end and again, loctited in. You can see in this shot, the venturi down in the tube, just past the air holes.

This is my cosmetically challenged refillable, commercial gas tank, it will be cleaned up and painted.
In the centre of the top you can see the 'Ronson' filler valve, which allows you, with an adaptor screwed onto a disposable plumbers torch canister, to fill the tank with gas (in fact not full, but only about 2/3rds, there is a stack tube below the valve inside that prevents overfilling). These are tested to much higher pressures than boilers, 360 psi.
The control valve isn't a normal steam one either, it has to be a special gas control valve. When I used to make these tanks, from thick walled brass seamless tube and flanged end plates, with an internal stay, the Ronson filler and control valve were always purchased, not made by myself.

A thread was put into the side of the jet tube holder and a brass screw fitted. This allowed easy adjustment of the jet backwards/forwards in relation to the venturi.

I tried the burner out not only with the brass rose that I had made, but also with a piece of ceramic burner material, made from an old boiler burner.
The brass one gave a much better jet pattern.

I hope this little vid shows what you need to know.
Not long to first run now.
Bogs