Aidan Stanger wrote:
Richard J. wrote:

As you say, the apostrophe has a circular ball at the top, but the
dot under the T of "ST." is square. Also, several letters are
narrower than Johnston, and the E and K have subtly different
proportions. Looks like an amateur attempt to copy Johnston. I
wonder why.

Because the real thing was hard to get hold of?

Surely not at LU's HQ station?

I've heard of one such font called SubwayLondon. Could it be that?

I haven't managed to find a full character set of SubwayLondon. The name
suggests it's an unofficial American clone of Johnston.

I think it's more likely that the sign was put up in the 1970's when LU
were starting to redesign Johnston. It might contain some experimental
variations that were not adopted for New Johnston.
--
Richard J.
(to e-mail me, swap uk and yon in address)