After going to the effort of finding the correct Harbor Freight riveter and having two of the nose pieces machined by Zenith to work with the A4 and A5 rivets, the time had finally arrived. On the very first rivet, the riveter pulled the rivet but did not release the mandrel. I released it by disassembling the unit, but it did it again on the second pull. Back to Harbor Freight today for an exchange. After switching to the ZAC riveter (more recoil), I was able to complete this phase of the job. It is finally coming together.