I've just bought a BR Kings Cross suburban lines WTT from 1971. It
shows a path for stock transfers from Neasden to Drayton Park as
follows.

Neasden - Farringdon (CWL) - Barbican (CWL) - Farringdon (CWL) - Kings
Cross LT (CWL) - Kings Cross - Holloway South Down - Finsbury Park No.
2 - Finsbury Park No. 1 - Highbury Vale - Drayton Park.

The trips were topped and tailed by battery locos and contained at
most three cars of 1938TS. Maximum speed through CWL platforms was
5mph.

I know that by 1971 the usual stock moves route, diverging from the
ECML immediately north of Finsbury Park then on to Highgate, was
closed but I have questions about this path.

Neasden was a Bakerloo Line depot but the Drayton Park - Moorgate line
was advertised as being part of the Northern Line. Was it
operationally part of the Bakerloo (in the way that the ELL was
advertised as Met Line but was operated by, was it the District)? Or
was it worked as Northern Line but went for overhaul via Neasden to
Northern Line depots and Acton?