Lancaster Cockpit

Yesterday evening I was watching an old favourite war film of mine, ‘A Matter of Life and Death’ with the fantastic David Niven (God rest his soul).
Anyway, I was wondering which Lancaster’s cockpit was used for the cockpit scenes where Niven’s character, Squadron leader Carter, is talking to Radio Operator June (Kim Hunter), and preparing to meet his end.
Was it the cockpit of a complete Lanc, just the cockpit area, or a convincing mock up I wonder?