Help identifying a 1930 Omega Watch Co Tissot

Hello everyone,

This watch recently came into my possession, and I would like to restore it as close as possible to its original condition. It is currently non-running and missing several components, including the crystal, hands, and buckle.

I have already sourced a donor movement (Cal. 20) with a very close serial number. However, I am having difficulty identifying the exact model to correctly source the remaining parts - especially the hands.

Could anyone help confirm whether the watch is original, assist with model identification, or share reference images/catalog entries of similar pieces?

Thank you very much in advance.

Some additional Info.

Movement:
CAL.20

Serial:
778.428

Box engraving (internal):
METAL
PLAQUÉ D'OR LAMINÉ
GARANTI 10 MICRONS

TISSOT
FAB SUISSE
SWISS MADE

RC
672314

Box engraving (external):
ANTIMAGNETIQUE