This is from Sheldons page, and is how i figured the date of manufacture. it said the 1974 & up had a W as the first digit?.this one doesn't..it's A6334
1967 - 1973
Yet another number system was introduced in 1966. This new system applied to the high-end (i.e. Reynolds 531) frames, and involved the placing of a character at the beginning of the serial number. The character began at the start of the alphabet, and indicated year of manufacture. Detail about the numerals that follow the alphabet are sketchy, and are presumably sequential serial numbers of some kind.
1966: A, followed by four numerals
1967: B, followed by four numerals
1968: C, followed by four numerals
1969: D, followed by four numerals
1970: E, followed by four numerals
1971: F, followed by four numerals
1972: G, followed by four numerals
1973: H, followed by four numerals