looks like an omega with a little bit of water damage. do you have any other photos??
Many omegas didn't have a sub-brand - the only other information you can find is the serial number and case reference number which can be found on the mechanism and inside the back of the case.
not a century - it's an omega omega.
the only solid identifying information will be inside the watch itself. have the crystal replaced (20-30$) and then decide whether you want to have the mechanism serviced.