Not sure who made it, but that is a great pic. Those machining marks in the slots were what I was talking about with the one that SA Inc just sent me. I see it has the step behind the sight base, but can't tell from the pic if it has the 45* bevelled radius on the front end. Would you mind posting another picture that shows the front a little more clearly? If you don't mind, I'm gonna go ahead and link this to the "How to ID USGI Forged or USGI Cast Flash Suppressors" thread.