The neutral safety switch isn't the issue if the engine is cranking. You do have a switch issue but it isn't what is causing your no start problem.
I seem to remember in vehicles of that vintage they had a fuel cutoff switch that activated in an accident to shut off fuel pumping a stalled engine. Some were accidentally triggered when the vehicle gets a jolt. I don't know if your RV has one but it would be something to research and an easy fix. Generally on Ford's they were located behind the passenger front kick panel.