This watch is in very good condition except for the rear cover which has 3 chips out of the glass . The crystal is in good shape as is the movement, runs fine. The numbers on inside of back cover have J WYSS FILS CNXDE FDS wiht NO. 502 in center. In side back of watch has the numbers 16831 on the advance/retard arm and on the edge of the main portion under back cover has 0370 on the edge. Thanks for any help you can give