1963–?27 variants
The first Carrera: a three-register, 12-hour chronograph on the Valjoux 72 in a 36 mm case with long faceted lugs. Jack Heuer's legibility-driven design moved the 1/5-second scale onto the crystal tension ring, keeping the dial clean. Introduced in 1963; the earliest known serial is 53781 (a 2447 N). Dial-code suffixes after the reference identify the dial.
Faded ends mark approximate or unknown dates. Years are as stated by the cited sources.
First-series white-dial Carrera 12 with uniform (non-contrasting) registers, thin bevelled baton markers and narrow hands. Covers both the original eggshell dials and the later silver-white dials; sub-types follow the dial finish and caseback.
First-series black dial ('N' for noir) with matching black registers, white print and thin baton markers.
Specs shared by all variants. Variant pages show where a variant differs.
White first-series dial with a blue decimal-minutes track, a scale Heuer carried over from its pocket chronographs. A Fisher-branded 2447 D (serial 56355) is the earliest polygon-back Carrera HODINKEE had seen.