[Lynn Eades]

Jordan, Great thread good on you! Anyhow, back in the thread you were talking about countersunk screw heads standing proud in the holes, Thats because you have used American std fasteners instead of the British standard. Instead of using UNC/UNF fasteners on yourcarrier you should be using BSF fasteners. They have a different spec and will fit the countersink holes properly. Metric countersunk screw heads are pretty close too.
On the riveting thing , if you can get some help, heat the rivet white hot, throw it in the hole, get your mate with a heavy shaped (to the profile head you want) "dolly" up against it and like greased lightening pean the other side to the profile you want using a rivet gun/kango hammer etc. The problem is you have to make up tooling to suit the gun your using. Ihave found that unless you are square on it is very easy to "smear" the rivet side ways and it takes much longer to get it out than mess it up.
These rivets are supposed to be done hot. As they cool they shrink and hence, tighten. Note I made my tooling ( the bit in the rivet gun) out of 4140, It tends to harden with use and keeps it shape. The big side clearance in the rivet hole allows you to get the rivet in the hole when the rivet is hot and expanded, without the surrounding metal sucking the heat out of it before you can deal to it. Hope this all makes sense. Lastly the rivets "form" to the counterink in the plate so you do not need countersunk rivets, - the prefomed head of the rivet goes on the inside, the shank fills in the countersink,and forms the nice rounded head on the outside if I remember correctly