Croton Aquamatic 550 Swiss made 17 jewel automatic movement winds, sets, runs as it should after recent cleaning and oiling.  Stainless steel case show minimal wear; dial, hands, and markers very good to excellent except that dial has some aging in the 4 to 7 o’clock area.  Crystal has a small crack at 3 o’clock; no leaks.  Probably manufactured c. 1960.