Hi Oskar,
Welcome to the OF. To me, the watch looks legit. it is one of those millions of Quartzwatches, Omega produced in the 80th mid of the quartz-crisis.
Seems to be in good condition case-wise and if the movements works it should be all ready for wearing.
Interesting here could be, if the case if full gold or gold plated but for this you'll have to provide a photo of the inner side of the case back.
There should also be the reference number of the watch and perhaps (with a little luck) a hallmark telling the gold content of the case or at least if it's goldplated only.
Cheers,
Winny