door hitting fender is typical indication of bad front cab mounts causing the front of the cab to sag down
if you ever see pliers bent front door edge (cringe) it is for this reason
motor oil soaked after 60 years tends to soften rubber
rusted lower fender mount will also cause the fender bottom to ''relax''
another cause for front cab sag is removal of the trans x-member to install an automatic trans
that trans x-member also supports the front cab supports