Okay; stumped!!!!

sticking throttle would be my greatest concern. Early builds didn't have the free throttle return slot in the throttle pressure/kickdown linkage. The one thing worse than seeing a run away Plymouth nearly run over some kids... is being one of those kids.
The stem and knob in the headlight switch are made together / don't come apart. You'll have to hammer destroy that switch to get your knob with stem out for reuse in new switch. Good luck with it.