I don't suppose the area where the 2Xs are found was originally an addition like a deck or open porch built before the 80s? Many states prior to the 6th edition of the NBC let tons of junk slide, windows, doors, some additions, (decks) roofing, siding, etc. without pulling permits. In 1982 Ma, all one had to do to get a license handed to them was have an employer vouch for you regardless of qualification. By 1987 it all changed in Ma, so much bad work had been done you couldn't sneeze on a house without pulling a permit. By 1990 One had to register with the HIC to do repairs, (even if you had an unrestricted CSL. By 1992/93 the majority of write-ups in the "Bulletin" State contractors rag, went from amendments to the current code to contractor fines and license suspensions. Many homeowners think they can still reconfigure the weather tight and or structural integrity of their home however they like, because it's their home.
Work smart not hard!
Never bite the hand that looks dirty