Gillette Date Codes

This table is available in various forms. I've just replicated it in a format that makes the most sense to me and I only cover the Adjustables.
(Clicking on the underlined razor name will open the page in a new window)

MODEL DATE CODE / (DATES)
Serial Toggle Only A1      (1st Quarter of 1955)
FatBoy D1 to H1      (1st Quarter of 1958 to 1st Quarter of 1962)
Executive (Gold) FatBoy D3 to G1      (3rd Quarter of 1958 to 1st Quarter of 1961)
Red Dot Fat Boy Only D1 and F4      (1st Quarter of 1958 and 4th Quarter of 1960)
Standard Toggle Only D1 and F4      (1st Quarter of 1958 and 4th Quarter of 1960)
Chrome Toggle Only F4      (Only 4th Quarter of 1960)
Bottom Dial Only F4      (Only 4th Quarter of 1960)
Slim F2 then G3 to N4      (2nd Quarter of 1960 then 3rd Quarter of 1961 to 4th Quarter of 1968)
Aristocrat Slim G3 to M3      (3rd Quarter of 1961 to 3rd Quarter of 1967)
Super Adjustable 84 (Black Beauty) N3 to V4      (3rd Quarter of 1968 to 4th Quarter of 1975)
Super Adjustable 109 Gold O1 to P2      (1st Quarter of 1969 to 2nd Quarter of 1970)
Super Adjustable 109 (Black Beauty) O1 to W3      (1st Quarter of 1969 to 3rd Quarter of 1976)
Super Adjustable 109
Plastic Base / Gillette Knurl
X1 to B4      (1st Quarter of 1977 to 4th Quarter of 1981)
Super Adjustable 109
Plastic Base / Diamond Knurl
A1 to I2      (1st Quarter of 1980 to 2nd Quarter of 1988)