It can’t get any more classic than the Patek Philippe 570. The 570 was manufactured from 1938 to 1972 in yellow, white, and rose gold, as well as platinum, steel, and two-tone combinations. The reference came in a variety of designs, featuring baton indices, numerals in both Roman and Arabic, applied Breguet style numerals, and two and three-tone dials. The flat-bezel case was a significant increase in size versus the first Calatrava introduced, the 31mm Patek Philippe Reference 96, first manufactured in 1932.
The 570 used manual calibers 12-120 SC (center seconds), 12-120 PS (subsidiary seconds), 12-400, and the 27 SC. The 12-120 PS was the most common movement used, a 12 ligne in-house movement.
This research focuses specifically on my personal favorite, the stainless steel Patek Philippe 570.
Not covered in this research is the Patek Philippe 565, also introduced in 1938 and featuring a 35.5mm case, but with a screw-down caseback.