| G1 | Kent Sussex and Surrey | Winbolt, S.E. | 1939 |
| G2 | Somerset | Winbolt, S.E. | 1939 |
| G3 | Cornwall | Lambert ,J.W. | 1939 |
| G4 | Devon | Loveridge, F.L. | 1939 |
| G5 | Derbyshire & Peak District | Mutton, F.C. | 1939 |
| G6 | Lake District | Palmer, W.T. | 1939 |
| G7 | Suffolk & Cambridgeshire | Messent, C.J.W. | 1949 |
| G8 | Norfolk & Isle of Ely | Harland, E.M. | 1949 |
| G9 | Wilts & Dorset | Muirhead, L. Russell | 1949 |
| G10 | Hampshire & the Isle of Wight | Winbolt, S.E. | 1949 |
| G11 | Herts and Bucks | Winbolt, S.E. | 1949 |
| G12 | North Wales | Palmer, W.T. | 1949 |
| G13 | Berkshire & Oxfordshire | Jowitt, R.L.P. | 1950 |
| G14 | Kent | Banks, F.R. | 1955 |
| G15 | Surrey | Banks, F.R. | 1956 |
| G16 | Sussex | Banks, F.R. | 1958 |
| G17 | London | Banks, F.R. | 1959 |
| G18 | Warwickshire & the Shakespeare Country | Banks, F.R. | 1960 |
The Penguin Checklist Project
A growing list of the books published by Penguin
The Penguin Checklist Project 
Re dates. All up to G6 were 1939, G7-G12 were 1949, G13 1950, G14 1955, G16 1958, G17 1959. I believe!
I see you are missing the Xmas Books list:
CHRISTMAS BOOKS Edition
Grey, Thomas Elegy in a Country Churchyard 250 1928
Bolitho, Hector A very Early Victorian Christmas 300 1929
Ferguson, John The Dog 300 1930
Coleridge, Samuel Taylor The Rime of the Ancient Mariner ill Duncan Grant 700 1946
Beerbohm, Max The Happy Hippocrite 500 1948
Carroll, Lewis Alices Adventures in Wonderland 500 1949
Chaucer The Nuns Priests Tale 1000 1950
Rieu, EV St Marks Gospel 1250 1951
Cowper, William The Diverting History of John Gilpin 1600 1952
Gilbert WS Selected Bab Ballads 1500 1955
Linklater, Eric Private Angelo 2000 1957
Various Boxwood & Graver 1500 1958
Rolph, CH The Trial of Lady Chatterley 2000 1961
Woolf, Cecil ed Without Prejudice…. Baron Corvo 600 1963
Calman, Mel For Such as are of Riper Years 2000 1965
And the Illustrated Classics:
PENGUIN ILLUSTRATED CLASSICS
JANE AUSTEN PRIDE AND PREJUDICE C1 1938
LAWRENCE STERNE A SENTIMENTAL JOURNEY C2 1938
EDGAR ALLEN POE SOME TALES OF MYSTERY & IMAGINATION C3 1938
HENRY THOREAU WALDEN OR LIFE IN THE WOODS C4 1938
ROBERT BROWNING SELECTED POEMS C5 1938
DANIEL DAFOE ROBINSON CRUSOE 1 C6 1938
DANIEL DAFOE ROBINSON CRUSOE 2 C7 1938
MELVILLE TYPEE C8 1938
RICHARD JEFFRIES STORY OF MY HEART C9 1938
JOHNATHAN SWIFT GULLIVERS TRAVELS C10 1938