They're called directories, Red - trade, or post office, sometimes almanacs.
They were still being produced in the 1940s
Dawn M
Of course they are Dawn, sometimes at my age, even on what was my birthday, a word escapes me for a few seconds, minutes etc. etc.Regarding the thread, unless the site is on or near the edge of the SW2 postal district I would confine my search to that immediate area, he (or she?) wouldn't want to go far I would think.