Just for people to know, the reg is fully adjustable with a backwards purge system on the reg, to drain the air out of the macroline before you unscrew the tank.
Its an Air America Abbadon 04 and although the company no longer exists you can get spares if they ever fail from AAchopshop.
Sweet marker m8, Id take it off you right now for asking if Paypal wasnt ****ing around with 400 quid of my money.