I recently acquired an Autavia 11630 Tachymeter (black face) with serial 260584 if it helps. I am guessing it is near the beginning of the 11630 production.
-Daniel

: Hi David.

: Firstly, congratulations on the Autavia.

: Secondly... well, we're still working on the serial numbers to be
: able to nail it precisely but the serial number for your Autavia
: suggests mid-70s. If I were pushed, I'd say 1975 with the
: possibility of late '74.

: It helps where we can get serial numbers for watch models where we
: know the year they were introduced, because the lowest serial
: number gives us a number that cannot be before year X... but
: there's still plenty of guesswork involved!

: Mark