Hi, I've had a look through the advanced side of the Ranfft database and haven't had any luck in finding this Gallet movement. It is a size 10/0 or 9 3/4''' or 21.77mm. 15J, 4 adj. Serial number is 297453. It's in a Niello case, which is .935, with Swiss hallmarks. As it is .935 rather than .925, this suggests that the watch and case are fairly early, predating the 'sterling silver' standard.
Anyone with any wisdom on this movement?