What time period would this Swiss watch be? It's not machine smooth like the 1940's onward. It's a 12s with 17j adjusted 3 positions and double roller. It needs a good cleaning and a case screw replaced.

Here's the movement side.

Hi Roland, guessing here but it looks like 1910 to late 20's to me.

Agreed. I'm currently carrying a 1926 Elgin 12s with the exact same dial as that one, as well as have a 12s Gruen from the early 20's having the same dial....so it was a popular base design during that period of time.

They just changed the name.

Regards! Mark

Thank you Ray and Mark. I agree with late 20's. I've just got to gently clean up the dial.
I have another similar movement that is from the same era, but with porcelain dial, so when I came across this with the metal dial thought made 1930's up to WWII.

Here;s a picture of the other Swiss movement that is very similar, but has mainspring barrel covered under the plate.