Help in caliber identification

[Dmitry]

Working on this 19ligne 15 jewels caliber and need a new staff, or the whole balance assembly. The problem is that there are no marks to identify this movement. Nothing on the dial.

The nickel case says Sonwite. Balance cock has F and S for the American market, the balance cutout has the number 25 stamped and a larger capital L stamped in the groove under the balance cock. There are no other marks. 

Can anyone help identify this caliber to order a new stauff or find a new balance assembly?

Edited May 13, 2022 by Dmitry
typo

[Kalanag]

What‘s the diameter of this movement?

[mikepilk]

4 hours ago, Kalanag said:

What‘s the diameter of this movement?

If it's 19L, then 42.86 mm

I had a look in Best Fit to try to identify the keyless work, but nothing close.

[Dmitry]

14 hours ago, Kalanag said:

What‘s the diameter of this movement?

around 43, fits ligne 19. Was cased in a SNOWITE.

[Kalanag]

I havn‘t found this caliber. Seems not to be a major manufacturer.