The work you are doing reminds me of my early days in the Silicon Valley tech industry... we'd dumpster dive behind various tech companies (like DEC, or Apple, or SGI) and find old hardware like your drill press... and then have to figure out how to make it work, all with nothing but voltmeters, oscilloscopes, and catalogs of microprocessor chips that showed processor pinouts. (No internet, back then.)

We'd jury-rig the equipment to do whatever we needed it to do, build shit, and sell products.

Product development was only limited by how creative we could be with the stuff we salvaged or got second-hand with no manuals or cables...

I loved digging in, figuring out how some device worked, then trying to make it work differently to do whatever we needed it to do to work on our "production line". (Which mostly consisted of Henry, the EE, telling me what to do with the soldering iron before surface-mount tech took over.)

I can appreciate the personal thrills and fun you are having as you make these things work with elegant, hand-engineered solutions... but it is so far outside of my depth by now, that I can only view the waves as they crash on the beach, without understanding what is making the water move.

Still... I find all of your updates fascinating!