Here is a problem every shop person knows: you need a tapped hole in a big cast piston carrier, and there is no drill bit anywhere near the size required. The maker's answer was to bore the hole out on a radial drill or milling type machine, and the hole came out fine for tapping. That is exactly the kind of improvising I enjoy reading about.
The setup is worth a close look. The machine has handwheels, graduated feed dials and manual levers, with the spindle carrying a cutting tool on an extended shaft that feeds into a boss on the top flange of the workpiece. Centering was done with a tapered center finder. One wrinkle: the chuck jaws are in bad condition, which shows in the numbers. The spindle alone has about 0.011 inches of runout, and adding the chuck brings that to roughly 0.024 inches.
The cutting numbers tell a sensible story. Roughing passes took 0.015 inches to the side and were pretty chattery, then a gentle finish cut of just 0.005 inches TTS brought it to size. The long thin cutter had a good bit of push off, so the maker compensated by leaving the hole 0.001 inches shy of the target, and it still tapped just fine. My view is that aiming slightly under on a worn setup like this seems a smart call. The maker also notes the machine is not precise and clapped out, and advises being gentle with worn-out machines.
The open question for me is chatter. The roughing was noisy, and with a long overhung tool on an imprecise machine I would want to know whether the finish surface suffered at all. Dark shavings piling out of a side opening in the hollow casting suggest plenty of metal moved.