At first glance this looks like a real Seamaster 300...but the devil is in the details. Look at the following: 1- Omega Logo 2- Bezel is not correct 3- Hands are not correct 4- Seamaster 300 on dial is wrong
Regarding # 2...there is a great post somewhere on this forum with a detailed list of all the correct bezels. I cant find the link, but here are a couple images. As you can see this bezel doesnt match, and is just off in general. Also note size and placement of top triangle marker.
Definitely a horrible fake. Another tell on this is the shape of the big triangle, it’s too narrow. However it is worrying that these are now produced without the stubbies and with a flat top A in waterproof on the case back - both obvious tells in the past.