MST - Roamer
MST was established in 1888 and it's brand for watches was Roamer. From 1952 the entire company was renamed to Roamer Watch Company.
In the long history of watches and movements producing MST also developed it's own alarm movement MST 417. First impression is that this movement is very simmilar to Vulcain 120 movement (see Vulcain). But technicaly those two movements are quite different. MST 417 has two spring barrels but only one stem and crown. It is in fact a modular movement, where alarm module is totaly split from the watch movement. Even though movement was of a very good quality it has a flaw in the hammer construction.
MST 417 was upgraded to MST 427 but just minor modifications were done. The biggest problem - hammer mount - was not improved. I have just MST 417 in my collection.
Crown in position 0: Winding forward - winding the alarm and activating alarm On (alarm is activated by the first turn of the crown, pusher at 2.00 jumps out). Winding backward - winding the time.
Crown in position 1: Setting the alarm hand, only by turning crown backward.
Crown in position 2: Setting the time.
Pusher at 2.00: If pushed while ringing, alarm is stopped. Reactivation of the alarm is done via the crown (see above).