I don't know much about this model, but crisp dial and hands pushed me to buy this cool 50's GP If you have any info guys, don't hesitate to share. ...
The difference between the 2 are the following: 11: screw balance 11.09: ring balance Thanks Ranftt for being a goldmine of information ! This movement was quite common to the alarm watches of this era. What is the diameter of this beauty ? Congrats !