"Mizter T" wrote

LNER - this is in connection with the abandoned Northern Heights
extension of the Northern line over LNER lines. I must admit I can't
remember whether any LNER trains would have actually served East
Finchley should the project have been completed.

Between July and September 1939 East Finchley was served by Northern Line
trains to High Barnet and LNER steam trains to Edgware. From then until
March 1941 steam trains continued to run to East Finchley, but the service
to Edgware was withdrawn to facilitate doubling and electrification. From
May 1941 Northern Line trains began to run to Mill Hill East, but further
work on the Northern Heights scheme was suspended for the duration, and
never resumed.

AIUI the eventual intention was for the whole passenger service to be part
of the Northern Line, with services from Morden via Charing Cross and Bank
to Edgware via Golders Green and to High Barnet, and from Moorgate via
Finsbury Park to Edgware via Mill Hill East and to Alexandra Palace (the
original branch line station, not the current one which used to be named
Wood Green). The LNER would have continued to operate freight services to
High Barnet and Edgware (as indeed BR did until the 1960s).

Peter