The steel cased 1675s are the classic GMT-Master and were made throughout all years of the model run (1960-1979). This model is referred to technically as the 1675/1 GMT-Master I, with the “/1” denoting steel; 1675/3 is the technical reference denoting the steel/gold cased version and 1675/8 the gold version. Notably, the 1675/3 and 1675/1 from the 1970s share some components and differ in others, as shown in the table below. This table only applies to the 1970s watches as the 1675/3 was not produced in the 1960s.
Part | 1675/3 (Steel / gold) | 1675/1 (Steel) | Same? |
Dial | Brown or Black Nipple | Black matte | No |
Handset | Gold | Steel | No |
Bezel | Gold | Steel | No |
Insert | Brown and gold (brown dials) or Black (black dials) | Red/blue or black | Black with silver writing can be seen on both models |
Midcase | Steel | Steel | Yes |
Caseback | Steel | Steel | Yes |
Crown | Gold | Steel | No |
Date wheel | White | White | Yes (also shared with gold model) |
Crystal | T116 | T116 | Yes (also shared with gold model) |
Movement | 1575 | 1565 (pre-1965) & 1575 (post-1965) | Yes (within accepted SN ranges) |
Bracelet | Two tone jubilee or oyster | Steel jubilee or oyster | No |
The steel model is split into two eras based on the types of dials used. The early dials were produced from 1960-1967 and are glossy (referred to as “gilt” dials), while the later dials produced from 1966-1979 are matte in appearance; both matte and gilt dials were produced in 1966-1967. Below are links to the dials available for the 1675/1. You can find the dials available for the 1675/3 and 1675/8 by going to the “Steel and Gold” and “Gold” menu headers, respectively.