I used an 80% from National Ord. Since the casting left the impression from the front pin hole, I drilled it first.All I used in the build as far as machinery, was a drill press with compound vise, dremel, files and die grinder and grinder. I got some cheapy 2 flute endmills from Harbor freight, used dremel bits in the drill press for the milling.Unfortunately, I forgot to take picts along the way, but I have another to do, so I'll do it then. I plan on getting a real mill, but the aluminum is easy to work with. I used an alum jig for the locations. I don't recall off hand who I got it from, though.