if you want to make a watch, a radio controlled clockwork would be the first choice.
this frame is simply pulled over it and provides the clockwork with a mount
Clockwork Dimensions: 72 x 56 x 19 mm
Radio Controlled Clockwork:
https://www.pearl.at/at-a-NX6324-3040.shtml
OR
https://www.amazon.de/St-Leonhard-Funkuhrwerke-Schleichendes-selbsgestaltete/dp/B089296VXH/
The author hasn't provided the model origin yet.