Wow! There is a acronyn out of the past---KAPL.
I worked for a sub-contractor to KAPL in the late 60's, early 70's, designing and building Control Rod Drive Mechanisms for them and the NAVY.
As I recall, we used our own internal manufacturing practices, but assembly tolerances were dictated within the contractural documentation.
Other than that we used GD&T from the original USASI Y14.5-1966 and later ANSI Y14.5-1973, and dictated all tolerances on the face of the drawing vs using "standard" tolerances
Such a document as you mention, and which I can't recall, would have at that time been proprietary or controlled.