It looks legit but It may be best if you tell us what price is being asked of you rather than asking what we would value it at since there are a multitude of ways to price a watch and the asking price is usually the most important.
ps I'd want to see better less blown out photos before buying that. The dial lume looks like tritium but the lack of contrast makes the hand look like grotty Superluminova, or perhaps tritium on the way to being patinated ie dirty. Better photos will help. Ask for them.
So $1600 landed? Yes that sounds OK. It does look like the hands are a little grubby near the centre but if the price is right maybe you can live with a bit of patina. Bear in mind you may have to service it sooner rather than later, but being a 7751 derived movement you have more options than those with the modular Reduced models.
Note while that is a late 80s/early 90s Omega box, it's probably not the one the watch came with which would have been the red type that disintegrates and would have matched the card wallet in colour. That wouldn't really bother me. You can't wear a box.
