You should take a look-see at the DIRECTV behemoth dish mount. They have vernier screws for both azimuth and elevation that make adjustments pretty slick.
Great idea, Satcom1. I added a 2 3/8" gate hinge under my motor bracket to prevent the motor from sliding down the pole when the U-bolts are loosened for azimuth adjustment
I split a section of 2.5" PVC pipe and used sheet metal screws to mount it under the bracket to keep from sliding down the pole. Even filed a notch for true south alignment.
As a side comment looks like you and I went to the same welding school! Several years ago I bought a 110v Lincoln mig welder.... one of the best hobby tools I've ever bought.