This engine psi gauge was removed from a BKS Airlines Vicker Viscount registration G-APNF same aircraft depicted in the photo. 
History of Picture Shown:
Registration: G-APNF
Construction Number: 225
Model Vickers Viscount 776D
Operator: BKS Air Transport (BK)
BKS operated a fleet of 4 odd Viscount 700's until replaced by ex B.E.A. Viscount 806X's . G-APNF is shown on its first visit to Newcastle on a quick turnround (from Jersey or Dublin as can be seen from the HMC mans white hat). Out of the fleet, this was an "odd ball" as it was fitted with "Slipper Tanks" this can just be made out on the wing to the right of the Engine. This is quoted as Test Equipment in The Viscount Book!!?? The Slipper Tanks were removed shortly afterwards as the extra fuel was not required for the sectors flown. 
inkFrog