Generally speaking, there are two generations of 1019 dials. The first generation, produced through the late 1960s, has a smaller Rolex wordmark at 12 o’clock, while later dials or service dials have “Rolex” in much larger text. There are also other subtle changes over the 1019’s run: the early examples will have a seconds track with 1/5 second increments also marked, a detail that’s lost on later dials. You’ll also notice the “Superlative Chronometer Officially Certified” text is shrunk on later examples. Since Rolex produced the 1019 across three decades, these changes really become emblematic of the Crown’s evolution: the brand name is printed much smaller on early examples, and there are those 1/5-second increments, theoretically (though perhaps not practically), making the Milgauss a useful tool for timing science stuff. By the 1980s, the Rolex font on the dial has become much bigger. Really, the print on the entire dial is crisper and sharper – the Milgauss had evolved into a true luxury watch, with its original anti-magnetic traits, while still there, now secondary. Later dials also lose the 1/5-second tick marks.
Another notable change over the life of the 1019 is the hands: Most examples are polished, with a ridge down the middle, while examples towards the very end of the model’s production (as well as later service hands) are flat and brushed.