Very Easily could have been the case - Jim & his wife being in their mid 50's, driving their just acquired, brand-new to them vintage vehicle cross-country well into the night, trying to make it back home (Virginia) prior to that next day; and at the dark of night, likely on a 2-lane, rural road, the vehicle, still very unknown to them, simply quits on them. ... That indeed could have been the simple case. ... And Should Most Definitely Be A Lesson To Be Kept In Mind Here. ~Skydogdang!
One thing that often worries me about a fresh restoration(from almost anyone) is they are often sold before they have a chance to work any bugs out, which may have saved Jim and his wifes life. Not sure if this is the case here but it may well be.