First of a kind for me, never seen any other dial like that. What caliber / size / serial? Looks like a 32-33mm case with early 30mm caliber.
@Tire-comedon : he said it's caliber 30T2, serial : 9mil - 10mil, size app. 36mm ?? I don't have a similiar dial, just have this one:
Yours look larger (see the space below the second hand track). Is it a 1953 RAF? The Omega logo and the shape of the hands are older style on the one shown by Timebandit.
The black dial watch is an omega www from the 1940s. The RAF'53 came with 3 dial variations - original TA, Bienne replacement TA and the much more common FA.