Way back in TIME

This is the movement of a watch that belonged to my mother. I have tried to date it but cannot improve on the fact that the back is inscribed with her maiden name. As she was married in 1935, we have at least an approximation. 

The watch is Swiss made by Cyma, but the bracelet is marked Gemex 1/20 12KT GF Made in USA.

Her father, my grandfather, used to travel to the USA on business and I wonder if he bought the watch or just the bracelet in the USA.

I find it interesting that the watch carried a 10 year warranty and was on the Non Pareil register.

Incidentally, my first watch as a youngster was a Cyma too, perhaps the brand was chosen for me because of this one.