Another full day of preparing these parts for shipment!
The last set of parts needed to be threaded (40 holes in all) each was a blind hole, and so I had to go down twice to be sure I hit the acceptable length. An interesting technique I haven't seen or heard of before but is built into the design of the hand taps. There is a hole at the top of most tap holders; its purpose is to slide a gauge pin into a vertical clamp of some sort, which in this case was the old manual CNC mill. You then slide the hand tool into the pin, and it creates a perfectly straight and stable way to hold the tap handle and still rotate and move it up and down. It's difficult to explain, so I'll upload an image of the setup I was using to thread all the holes.
After that, I gave all the parts a bath in soapy water, removing all the dirt and grime from sanding and deburring, then a rinse and spray down. From there, I packaged each part with toilet paper to ensure safe shipment! Since I've spent most of my time working on those parts, the shop has gotten somewhat messy again and will be spending the majority of tomorrow cleaning and reorganizing the tools.