This watch (dia 25.5 of the case) has a caliber that is smaller than c89 and
i can find the numer 42 under the balance. But that caliber number does not
exist. It probably is a 421? serial number is 1288641, case 1404009. It should
be from around 1957. Identification problem is that this watch has a subsecond
and not a sweep second like c421. Who can
help?