Of course records from executive departments which president trump took in his possession when he was president were in fact presidential records by definition. I am sure that all of the millions of other presidential records include plenty of documents from every agency of government they don’t all come straight from the executive oval office.
(2) The term "Presidential records" means documentary materials, or any reasonably segregable portion thereof, created or received by the President, the President's immediate staff, or a unit or individual of the Executive Office of the President whose function is to advise or assist the President, in the course of conducting activities which relate to or have an effect upon the carrying out of the constitutional, statutory, or other official or ceremonial duties of the President. Such term—
(A) includes any documentary materials relating to the political activities of the President or members of the President's staff, but only if such activities relate to or have a direct effect upon the carrying out of constitutional, statutory, or other official or ceremonial duties of the President; but
(B) does not include any documentary materials that are (i) official records of an agency (as defined in section 552(e) 1 of title 5, United States Code); (ii) personal records; (iii) stocks of publications and stationery; or (iv) extra copies of documents produced only for convenience of reference, when such copies are clearly so identified.