This is quit tough to categorized the whole Shanghai 611's series, since 100% original, untouched 611 are hardy found in the market. Uncounted movements or oldest dials had transformed to high value model 581 or had replaced the more reliable 1120's regulator unit in the old day.I can only identify each model by my own theoretical theory and the actual pieces on my collection....
A-611
A611
A611a
611
