1956 sealion mkII twin hose

[T.J. Gregory]

G,Day all.
I have aquired an older type of Britsh made two hose regulator in the Sealion mkII. 1956.
However, to begin an overhaul I need much more information than I already have. I have got breakdown diagrams and photos of what the unit looked like or should.
On the initial opening the main diaphram is not usable. Also the parts connecting to the high pressure seat( i think) are corroded and a brass type of screw is broken of inside.On the whole the rest of the parts and the body are fine or easily replaced with modern pieces.
Is there any of you out there with one of these types of regs that could possibly help inany way? Be it spare parts or paper information. Even a heads up on how to tune it would be good.
There is meant to be only four moving parts in it so should be relative easy.
Thanks for your time