More work on the horn which entailed a lot of disassembly, reassembly, and repeat. A couple of pilot holes in the horn were not completely drilled through from the factory, although they were in the correct locations. This is the 1st defect I have seen in the Zenith parts. Just drilled them out and proceeded normally. I had been dreading the right angle drilling of the horn extrusion. Bought a right angle attachment and chuck for this one spot. Turns out that even with this Frankendrill I couldn't get a good angle and I gave up that strategy. Ended up marking the hole locations with a pen, removing the extrusion assembly, clamping the bracket to the extrusion, and drilling the holes that way. More disassembly and reassembly, but I know the holes are straight.