Experiences harvesting cab body panels

[D-n-Tyke]

Looking to hear people's experiences harvesting cab body panels off donor cabs. Specifically I am thinking inner and outer rocker panels, inner upper window frame panel, outter upper windshield corner, possibly A pilars. Reading so many stories about how bad aftermarket sheetmetal fits I am wondering if finding a cab that has the parts I need and harvesting them off it might be a better option. Just don't know if they would get to damaged during the harvest to make it worth it (specifically the rocker panels). Swapping the full cab is not an option. Working on FIL's truck that he orsered from the factory in 1971, so keeping it as much original metal as possible.
What are your guys' experiences?