There are many threads on PB1 fakes - this one probably being one of the oldest.However, for instant Pit Boss 1 id look for the curve on the bottom of the orbital adjacent to the screw.Gen will have a nice 'dog leg' to it whilst the fake is usually much straighterFake on the left, Gen on the right.Also check for an [A] embossed inside the arm at the hinge end. There is also another smaller one embossed on the orbital.The dog leg curve is quite easy to see in an add whereas the [A] embossed inside the arm is hidden when the arm is fully open and is difficult to photograph unless specifically focusing on it.