Is there still an aircraft disassembly operation in Shelton WA? Decades ago I drove past it and saw 727s.
Components like pumps and engines are often re-useable, perhaps after overhauling them.
Parts that are out of production are even more valuable.
And as with B-52s, decades ago USAF was cannibalizing old 707-320Cs for tail structure and the newer yaw damper system to improve some of its KC-135 tankers. That pushed the price of used 707-320Cs up.