Very hard to be sure from those pics but the time is set so it obscures the main tell on the replica on the head on shot. May just be coincidence but my strong suspicion is that it is fake.
The date window is wider on the replica but the angle makes it tricky to see on the other photos.
Here's the difference - very small but what you should be looking out for.
As for the black centre on the case back, I've seen this on fakes but don't know if it was ever used on a gen.
You should ask for a close up pic of the dial with the hands not obscuring the date window and a pic of the case back showing the serial # matches that on the COSC certificate. If they can't be provided, I would not make an offer.