Hi Paul,

: Hi David - as far as I am concerned there are essentially two
: variations of the Autavia 2446C GMT as follows:

: The 1st execution has smaller sub registers, engraved backcase,
: smooth pushers, plain steel hands, white chrono hand and larger
: internal diameter bezel with fine teeth
: The 2nd execution has larger sub registers, plain/polished
: backcase, fluted pushers and bezel with larger teeth.

You introduced the differences of the case executions, also known from the chrono-only variants of the 2446C. IMHO, this is the correct way to reason, because the serial number is engraved on the case middle part.

: The bezels are not interchangeable.

Therefore one can distinguish the variants by looking at the bezel, in fact by counting the teeth per segment, 11 (first execution) vs. 18 (second execution).

: The combination of hands (hour, minute and chrono) on later
: examples vary depending on when it left the factory and /or
: service history. I do believe that the final example had the red
: accent hour and minute hands and red chrono hand.

Do we know whether the dials are interchangeable between these executions? I think so, because my watch -- like a few other found recently -- seems to have the later dial with larger sub registers and the earlier bezel with fine teeth.

Cheers,

Mick