I would never trust my life and an irreplaceable car to old tires. Tubes won't do anything to save you if the sidewall or tread experiences a catastrophic failure. They're not runflat inserts.
It doesn't matter how far you are going on the street, or how fast. If a front tire lets go without warning, you are either going into the oncoming traffic to the left or off the road to the right. And you can imagine the field day the lawyers for the guy you hit would have, when they find out you were knowingly driving on 40 year old tires.
I'll stick with buying the brand new set of L60x15s when they make them.
Here's my old tire story:
https://www.yenko.net/ubbthreads/showflat...e=0&fpart=8
This tire was about 14 years old with only 500 miles on it:
