But when yop open the back (which carries a lead-sealing to ensure
water resistance), you get a beautiful view: A Felsa Bidynator caliber,
probably from the second series (cal. 690), which doesn't carry a number. This
movement was the first one, where the rotor works in both directions,
and so quicky created enough power reserve. This movement was the
precessor of all modern automatic movements, as we knowm them today.
The best is still to come: This movement is equipped with a swan-neck
regulator. A detail, which is only found in (expensive) chronometers.
What that MIRA isn't a chronometer, I don't know.
And to top this story - this watch just cost me ~$4 (4 Euro) (and
about ten years of waiting for such a gem).
And no, this watch is definitely not for sale. Not for any reasonable amount