"Some"? Three USWA card-carrier shifts of us, dozen-plus per shift did more hand-finishing than not. 90% or so over corn-cob DC stick-weld cutback.
One old plain-bearing Niles of 30-odd inch swing had two thou of "climb" and drop-back in its spindle bearings on lighter work. Had two bearing fits on a 6" or so shaft that had to have four-thou of total ellipse filed-out, spindle STOPPED, then polished neat.
Usta be all in a days work "company" lathe or mill for tens of thousands of us, nationwide. Wages according that made waste of labour cheaper than rebuild of machinery a major part of what drove that. And that
any Machinist of the era, after all, knew how, HAD to know how, and had to know "when".
Nothing exceptional about it, my case.
Is a part of why we Old Farts get grumpy when a 30-something bitches his modern tinkertoy won't split a thou and deliver a mirror-finish, one pass, inserted Carbide tooling.
We don't want to send him back to filing and abrasives.
We are just jealous-grumpy 'coz we never had machines nor tooling even ten-percent as GOOD.