There were some cars with crumple zones back then, but you very likely do not have a crumple zone capable of protecting you. No matter how long your bonnet, you will probably take the brunt of the impact with your body in a car from the 70s.

Not saying don't drive it, I drive a 90s car with no airbags as a daily so I am only marginally better off.

They don't crumple much, despite the size.

What ever other car hit will so. In such an accident, the combined crumble zone is halved so. If you a concrete wall, good luck so.

I know what would happen if I have a serious accident in my week-end hobby car so. A likely hood that is significantly reduced by current fuel prices. And a serious maintenance backlog...

While you can't control all the outside parameters we also don't tend to drive them the same way.

Absolutely not! You tend to be much more careful with hobby cars then you are with average daily drivers.