Well, I see ThreeMan has more than adequately addressed the issue.
Nice job.
As far as Kimber's disconnector goes, the tunnel is not any wider. That donut is in fact there to take out slop and help prevent disconnector click. Unfortunately, it often leads to a situation where binding is present, limiting rearward movement of the trigger/sear/diconnector. In my experience, about 10% - 20% of the Kimbers I've done trigger jobs on are so limited by the disconnector that it's impossible to avoid half cock sear rub. This is not caused by overtravel stops on triggers, grip safety studs, or thumb safety studs, but simply an overly tight disconnector.
Maverick, the reason I asked about the disconnector that you bought is that it should not cause the situation you have. If the guy said it was GI, maybe it is, maybe it isn't. However, it is most likely severely out of spec. The bottom tab on the disconnector (the flat surface) is the link between the back of the trigger bow and the bottom of the sear feet. It sounds like when you pull the trigger, as the sear moves, the feet of the sear are slipping off the top of the disconnector tab, allowing it to snap back and catch the hammer's half cock notch. This can be caused by several things, such as overly shortened or excessively polished sear feet, an overly loose fit in the frame's diconnector tunnel, or the diconnector being too long in a couple different spots. I don't now what the deal is with yours, but if you paid any real money for it, I would take it back. If it was cheap, I wouldn't worry about it.