John Rowland wrote to uk.transport.london on Sun, 15 Aug 2004:

Thanks. I've seen a lot of street signs in North London that say something
like "Smith St N" instead of "Smith St N1". Do these signs date from an
interim period where names were unique to each sector but not to the whole
county? If not, what was the point of them?

I think these signs date from when London was divided up into N, NW, SE,
SW, etc, without numbers. Then they subdivided it: N1, SW2 etc, and
now, of course, it is divided up even further into postcodes. No dates
for either, sorry! Although postcodes, I know, came in during the
1960s.
--
Annabel - "Mrs Redboots"
(trying out a new .sig to reflect the personality I use in online forums)