I just finished a 30T2 with centre sweep hand for a friend. Dial and movement shots, before and after. According to my reference, the 9million serial number places this watch circa 1925. But the watch is more recent than that, and has Incabloc shock protection. Based on style, I am guessing early to mid 1940s.
The images clearly show the copper colour movement. Somebody recently showed this caliber with a nickel movement. But I have only ever seen them in this colour.