Wait, you had 23 good pieces done and the spindle drive died anyway? That is brutal timing. Two hours in on a four hour cycle and you still had to start the offsets over from scratch? I would have been throwing tools across the shop (ok, not really, but I would have thought about it). Twenty years is a long run on one machine though, and a decade of you running it means you probably know every weird noise it makes before it quits. Did the other mill at least hold tolerance on the temp workaround, or were you sweating every cut?

That "cheat physics" line got me, but honestly the point keeps cooking while it rests.

Twenty years behind a chair and that wrist flick becomes muscle memory fast.