Does anybody remember mobile engine overhaul outfits?

I've heard stories from my father about mobile "in frame" engine machining. Pretty interesting process of cleaning up a crank journal after a spun bearing without pulling the crank.
After pulling the oil pan and removing main cap or connecting rod and whats left of the spun bearing,
One back wheel gets jacked up and put on a set of motorized rollers, with the transmission in gear this turns the crank at a slow rpm.
A strip of sandpaper is then held against the crank sort of like you would shine a shoe until the crank is smooth.
Then the crank is measured and a slightly undersized bearing is used to bring the oil clearance back to a within a reasonable amount.

Now this kind of stuff didn't come with a 100k mile guarantee, it was more to get every little bit of life out of an engine. Another thing was back then (pre 1960's) it wasn't uncommon to have to open an engine up and put a set of rings in it or do a valve job after 60k miles.

Mechanics back then didn't have the "remove and replace" mentality back then it was more like "remove and rebuild", customers weren't as fussy back then either.