Ny local smith won't do it either. he says the Bushy brakes are welded on so he can't do it. This is a few months after I got mine back from Kurt, so I know it can be done. I'll send mine out eventually to Kurt again 1) when I have the money and 2 in the winter when I won't be able to shoot as much, so I won't miss it.
They have pins, but they grind them down, weld over them and refinish the whole thing so you can't see the pin unless you look very hard. you see a small circle that's just barely noticeable. Some of the time they just pin the brake on and ship it out, but I think with the factory rifles (AK SHorty and the M4) they add this extra process to make it a cleaner looking install. I have an AK Shorty with no pins visable and I've seen the M4 14.5 with no pins visable, but I've bought from the EE an M4 16 incher with an M4 tacked on to that with the pin showing and a 20 inch with an AK brake with the pin showing. Why they do this, I'm not sure. Probably just to save money.