Need help Omega 166.077

Hi to all!
A few days ago I saw this Omega Seamaster 166.077 for sale to a local web site.
I don't to much about this model, and I notice that there are some with wrong parts, even on Chrono24.
So, I need your help in order to know if it is legit.
Thanks în advance!

Here are the seller pictures!

Looks very original from what I can see. The dial is interesting, as it has some unusual typeface, but I would expect it to be Tritium and from a late production run in 1979 or later? The bracelet is original, as is the extension. It has a fat font non serif bezel, which may or may not be a service item. I think if the extract came back as late as I think it will, I would be inclined to think it was contemporary and original.
The watch looks like it has had a recent service from Omega, so the hands and crown may well have been replaced. Photos lack definition for any conclusion to be made.