@Darryl Durdin Vapalux lamps where manufactured in Halifax, West Yorkshire, hence they put Halifax on some of the hoods, I’m guessing your hood is from a Vapalux 300.
Vapalux 300, steel tank. Probably from 1945, have a close look is there a date on the hood.. Should be fairly straightforward to get it going.
It has the (new) collar with one triangled hole, replacing the multi-slotted ones in the end of 1944. This also means you do not have to dig for a holed glass and can settle for more common ones. Around this (war-) time similar 300 model Vapa's appeared without any marks (no embossing) in the ventilator but usually with a crowsfoot and year stamped into the lower brass rim. That enamelled top looks clean from here, and these are nice lamps to use if you can control the rust.
Try to find Ian Ashton's book about Vapalux, everything is explained, this is made after June 1944 or in 1945...
Ian Ashton's book can be read here:- Vapalux and Bialaddin Pressure Lamps by Ian Ashton | Blurb Books UK