This data has been verified against a physical copy of the map.
Standard Pocket Map
Map of London’s Underground Railways
A new design for an old map
Waterlow & Sons Limited
Folded: - Unfolded: 227mm X 161mm
First edition Harry Beck.
Sold on eBay for £236.99 in June 2008.
Signed edition sold for £3,200 at Transport Auctions London on 17th Feb 2018.
Anne Letch lists a January 1933 map with o/p "L.P.T.B. 55 Broadway, SW1". The LPTB did not exist until July 1933, so the o/p is later than the map. Letch quotes the reference code as "750M - 1-33", but some collectors doubt this and believe there was a single edition in January 1933, with code "(750M - 1-33)". I have a variant of this map that was printed on thin paper, rather than card, and which has the o/p "L.P.T.B. 55 Broadway, SW1", but its printed content is identical to that of the card map. In particular, the code is the same, "(750M - 1-33)".