Crankshaft grinding - video

[Toolmaker51]

Not I certainly, least-ways in person, yet aware; especially tricks performed completing in frame overhauls.
Quite a range exists in 'bolt-on' aka 'portable' machine tools; journal squirrels, facing machines, boring bars (ie Frank S's avatar), keyway cutters, hand lathes... There might be portable broaches; mass needed to deliver rigidity makes that hard to imagine.