dpb wrote:
....

Of course, ideally one would remount the full jamb to get it coplanar
and adjust the width to compensate or the wall, but that's more effort.

I'm assuming from the age the door casing/frames are built up of stock
not prehung units. If they are prehung, your choices are more limited
since the jamb is probably not re-positionable. At that point I'd look
at rehanging the door and compensate as needed.
....

Oh, BTW, by coincidence the last issue of FHB has article on adjusting
prehung units; includes example for non-coplanar walls as well...

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