I am a second owner, although the gun was not shot before I got it. I don't have a build sheet - which is for the better since every time I take it apart, I find something new. It was built by Ned Christiansen, who is a great guy and a genius. The main line in this build was extreme weight reduction while maintaining all steel construction - metal was removed from all places possible and impossible.
Rear sight is Ned's rendition of how it is supposed be done for one-handed manipulations. Combined with flattened top of the slide, it makes a big "hook" with very reliable engagement.
Grip safety: I believe Ned holds a patent for this mod. Some folks - and Ned is one of them - have issues with traditional GS due to pivoting nature of it. When one tries to get a very high grip on the gun, it is possible to provide more upwards pressure on beavertail than forward pressure on the pad, and gun won't fire. Ned "splits" grip safety into two pieces so beavertail portion is static and doesn't move at all. This is how it looks on the gun
RDS part is a proof of concept. The can is neutered - something to do with Michigan class III laws...He just thought that suppressor can be a carrier for RDS and built that mount. I haven't pursued getting a real can to test it out.