information on this (Omega?) caliber

Hi everyone, this is my first post.
I come to the point.
Two weeks ago from an Austrian seller, I bought a watch with a black Omega dial, changed to sepia, Arabic numerals in ocher yellow with lumens not always properly set in yellow tone, hands with luminescence, only hours and minutes, no seconds.
The 37 mm wide case without crown is in chromed brass with fixed spider lugs, steel caseback with serial number on the outside, inside it has the circle decoration, which was also used to cancel the brand of the case.
the crown is anonymous and in chromed brass.
The movement is 29mm wide and looks like the smaller version of the 19 Omega line. presents the Omega logo on the bridge of the balance as a decoration on the same, moreover it is completely gilded.
I bought it for the low price, now I would like to know if the mechanism, the dial and the hands are Omega, what kind of caliber it is etc ... if it is worth looking for a suitable case ... if yes, I would like you to tell me via photo, its proper case.
thanks to those who can help me.

As some Italian collectors have told you, it's a marriage.

ok but the mechanism and the dial is Omega? if so what could be his right case?