amanico[JLC Moderator]
400104
Bingo. It is indeed a 17-29 CH.
Here is the document which helped me to identify it:

The 19-9 being slightly differently designed, and too big for the case of this Chrongraph.
Best,
Nicolas
An Olde English phrase
By: Tick Talk : December 23rd, 2012-07:36
18th century - an expression of disbelief was to push one's cheek out with the tongue. Today, the phrase substitutes for the act. I think there are many similar actions used to express feelings, such as biting one's thumb, thumbing one's nose or, in moder...
Repair
By: bon092 : January 6th, 2013-09:34
Amanico, I had a repair to my Minerva Villeret 1858 13-20 Crono. I lost one of the push buttons, so it had to go back to the Minerva shop in 2012 to replace that one. They found that the movement had sufferd from moister inside and it could not leave the ...