Although this is a crude introduction into the matter, it should provide some help in recognizing the differences, especially in the dials. In-depth articles per model will follow once I find the time – these will feature the various references and dial variations. For now a few notes are to be found below the pic.
|pictures sourced through the Antiquorum database|
6511: Calibre 1055. First Day-Date to be available to the general public. Radium for luminescence. Available in yellow and rose gold. Alpha or Dauphine type hands. Arrow head markers. Early examples may include the depth rating on the dial.
6611: Calibre 1055b, improved 1055, note the Superlative on the dial. Radium for luminescence. Also available with smooth bezel (6612) or diamond bezel (6613). Available in yellow gold, rose gold and platinum. Alpha hands. Arrow head markers.
1803: Calibre 1555 or 1556 (after ’65). Hacking seconds after ’72. Either radium (swiss) or tritium (t swiss t, after ’64) for luminescence. Also seen with sigma signature (σ t swiss t σ). Available with many different bezels and even case finishings, amongst which the 1802, 1804, 1805, 1806 et cetera. Available in yellow gold, rose gold, white gold and platinum. Early transitional models can be found with the Alpha hands. Other examples used include the Pencil (most common), Cigarette and a special seventies wide Pencil type. Early models can sport the 6611 type dial with arrow head markers, while others use regular batons, painted roman numerals (a first), wide batons or Claw-type markers.
18038: Calibre 3055. First Oyster Perpetual Day-Date with quick-set Date and sapphire glass – these were first introduced in the OysterQuartz Day-Date a year earlier. Tritium for luminescence. Available with many different bezels. Available in yellow gold, white gold and Tridor – note the rose gold and platinum are now missing. Pencil type hands. Lot’s of dial variations including special materials like burl wood, finish in Tuxedo-style, either painted or applied roman numerals et cetera. In contrast to the Pie-pan style dials of earlier Day-Dates the 18000-series uses a flat dial.