Comparison of Autavia GMTs (Manual-Wind)
	The first version of the Autavia GMT was the Reference 2446 GMT, with a screw-back case pushers are smooth main hands are "plain" (luminous inserts, but no red inserts) second hand (on chrono) is white Bezel is "Even numbers only" type
	In 1969, Heuer began using snap-back cases on the Autavias (Compressor case), so the Autavia GMT became the Reference 2446C GMT pushers are smooth main hands are "plain" (luminous inserts, but no red inserts) second hand (on chrono) is white
	In a "transitional" version of the 2446C GMT pushers remain smooth main hands remain "plain" (luminous inserts, but no red inserts) second hand (on chrono) is red
	In a "transitional" version of the 2446C GMT pushers are fluted main hands remain "plain" (luminous inserts, but no red inserts) second hand (on chrono) is red
	On final version of the Autavia 2446C GMT pushers remain fluted main hands have red inserts and red triangular tips second hand (on chrono) is red
	The Autavia 2446C GMT had unique time-of-day hands (not used in other Heuers) and a unique second hand on the chrono (thin red). As these watches were serviced, Heuer began to substitute newly manufactured time-of-day hands, with slightly different shape from original hands chrono second hand (from Monza) was shorter and thicker than original second hand
Additional Notes -- all Autavia GMTs, Reference 2446 GMT and 2446C GMT, were powered by a variation of the Valjoux 72 bezels are smooth, not ratcheted