1971-72 interior door panel question

[1971seeten]

I have a 1971 chevy truck and need to replace the doors. i found both doors at a good price but they are off a 1972. I wanted to use the metal inner door panels off the 67-71. The salvage yard said I have to use the panels off the 1972 because the 71 panels will not fit. Could someone tell me the difference and how hard it would be to modify the 71 panels to fit the 72 doors???