Colin Rosenstiel wrote:

As for the rolling stock, it looks like 1938 stock which would have
been authentic for the Northern in 1944, although I am not sure
about livery details being absolutely correct. That "No Smoking" window
transfer looks a bit post-war, but I am willing to be corrected.

The livery looks all-red to me, not authentic for 1944. Also the signs would have still said "NON-SMOKING" at that time. "NO-SMOKING" came later. And the lack of blast netting is wrong too.

I have been thinking about this. The 38 stock had cream window pillars
when introduced, didn't it? Like in this picture (of 1959 stock,
admittedly)

http://www.anorakheaven.com/photos/rs050.jpg

Maybe tube trains wouldn't need blast or blackout precautions if
German troops were in occupation?