The watch is only 26mm, say it a 23.7 S.T2 the movement was made some time in the thirty's. The seller is from Slovakia and wants $500. I do not think I would want to pay more than $350.00. Also what is the deal with the number on the case is it a serial number or a case model number. The hands and the dials type face matches a watch in a Journey Through Time Page 110 Plate 1708. I really love the case design.

 

this is outside my knowledge but I’d assume case number would match movement.

What exactly does the book say?

 

No it is not the same watch just a watch with the same Dial type face and the same hands.

 

Not generally, cases were made in one place, movements in another, then assembled.

 

The serial number of the case matches the movement's one. It is a nice watch but, if the dial has no hair or strach, I would not pay more than 200-300 euros. (Note that this size is for women.)

 

Maybe it is because of my poor English. I meant the case and movement serial numbers refer to the same years of production (early 1930's), then the movement and the case probably belong to the same watch.

 

Indeed!
Maybe they continue using serial numbers on gold cases to provide more data about a controled production, ie gold items intended to an international market.
On French made solid gold cases, there were also a serial number untill about the 50's. I guess Omega provided these numbers to makers, but I do not know the details.