Hi Spottydot,
A very nice watch, imho. Following dials decoration it should be something from the Art Deco period. Following the movement number it should assembled in 1920 or around, case number says 1925.
Stunning piece esp. with the original box surely a pretty rare find. Congrats to your hunt (need to add that I'm not an expert on pocket watches but also have one in Sterling silver from 1907 and I love it). Perhaps you could also find a matching golden chain some day to wear it.
Cheers,
Winny