Some kind of igniter?

[Tony Williams]

Can anyone identify this object?

It measures 154mm long, has a rim diameter of 37.5mm and a body diameter of 28.2mm.

 

[Chris 42 RQ]

MB ejector cartridge?

I'm thinking Martin Baker ejector seat !
Electric primed and long to hold a slow burning propulsive charge just enough to clear the tail before the rocket motor kicks in.

 

[exat808]

My guess is an electric engine starter. Clue from the letters "IPN" on the base. I seem to remember that IPN systems were a form of aircraft engine starters.

Just added "Iso Propyl Nitrate" = IPN a type of starter system used on Hunters and Lightnings and other jets of that era

Added - the No2 Mk3 version still listed as current by MOD- UN0315 - Igniters - Hazard Division 1.3G