This is what Sheldon had on his site:
Raleigh Bicycles 1925-Second WarBetween 1925 and the cessation of cycle production during the Second World War, letters prefixed or suffixed the running frame number although no indication is given of the starting point of the numbers. They seem to reflect only the number of machines produced whilst each letter was in use. All dating would therefore be approximate.
1925 - A1 ..............1930 - G94785 1935 - W71147
1925 - B34181 ......1933 - L84682 1936 - W93161
1926/27 - B56536 .1934 - T93945 1937 - Y184552
1929 - E15693 ......1934 - U14540
I'm guessing that when they passed Z, they went to AA, AB, AC and then AD. Based on the progression of numbers from year to year, I'd guess yours would be from about 1940 or 1941.
I used the word "guess" twice there, so that means very close to nothing.
