The model number (we call it a case reference number) is 2504. It has a caliber 283 from somewhere between 1947 and 1950. The dial has been refinished (repainted) at some point in it's life. ps - People do have jobs and lives, so it might take more than an hour or two for responses.
How much it cost or how much is it worth? Worth can be determined by searching eBay and other sites for completed auctions with that reference number. No idea on how much it originally cost.
Go to eBay. Do an advanced search and enter Omega + the reference number. Click on completed auctions. That should bring up what they have recently sold for. This is probably the best way to determine value. But if you just want a wild semi educated guess.....250-500. The repainted dial will turn off a lot of potential buyers. I say have the crystal polished and wear it in good health.