The bezel of my watch broke and I was unable to obtain an original  spare part. Since I couldn't stand the "tuna can" look of the  bezelless watch, I designed this replacement from scratch by taking  measure of the watch and playing with openscad's hull and minkowsky  operations.  Both versions print fine without support with their dial side down.  The single-piece version requires bridging. I used 0.55mm extrusion  width and 0.25mm layer height on my Reprap.