Already purchased for £275 and thinking now that it may be a Franken. Caseback serial is 135.007-66 (indicating 1966?) Movement serial begins 213***** indicating 1964. Also the movement caliber is stamped 285. Cant find any references that say these movements are original to the seamaster 30. Usually it's the 286 caliber they came with although there are some out there with 285s (other Frankens?) Cant' see 'Swiss Made' at the 6'oclock although it could be hidden by the retainer ring. Any help and advice appreciated.