It’s not a great photo but my gut feeling is that the dial is repainted. Spacing in OMEGA is very uneven and the painted marker at 10 is too close to the applied marker. Etc. The seconds hand is too short also.
TONS of sold 2603's for sub-$1000 on ebay, so the price isn't right at all. I found the original ebay link, and the conversion to the site here seems to have messed with it, I don't think it looks as suspicious on ebay (https://www.ebay.com/itm/235822105942?).
Likely a really nice reference, for about 2x a market price.