I'm surprised at you, mfree.
Don't you know that the magic of old cars extends to their ability to throw a protective "deceleration trauma prevention" forcefield around the occupants that will allow them to escape with no injury?
The worst accident I've ever seen was very similar to the one you describe.
A massive old Buick station wagon hit headon by a midsize Ford Taurus. At least I THINK it was a Taurus. I never could identify exactly what it was, other than some sort of Ford. It was far too torn up. Closing speed was estimated to be in the vicinity of 95 to 100 mph.
The driver of the Ford survived with substantial, but ultimately recoverable, injuries.
The family of 4 in the Buick?
The father's neck was broken, and his brains leaking out of his ears. The steering column shoved into his chest didn't help matters, nor did the engine that pulverized his body from the hips down.
The mother was ejected from the vehicle through the windshield. She left a good part of her skull behind on the top of the window frame, and a good deal of her skin behind on the glass enroute to a touchdown approximately 80 feet from the site of impact. Obviously she wasn't wearing a seatbelt.
The oldest daughter, probably about 5 or 6, had multiple broken bones. COD was internal bleeding resulting in multiple organ punctures from where her seatbelt pushed her ribs through her liver, spleen, lungs, and heart.
The only surviver was an infant in the child safety seat.
That accident haunts me to this day.