If your vehicle is too old to have smog equipment, that means that it's spewing toxic crap into the air every minute you're driving it.
That must be why trees, healthy and growing along the highways in the '60s and '70s, started dying after the catalytic converter was mandated.
If your vehicle is too old to have safety equipment, that means that your chances of dying, should you have an accident, are much improved.
Seat belts, shoulder belts, collapsable steering wheels are easily retrofitted. You are better protected in a tank than a tin can. There is a lot more mass to protect you in an older vehicle.
If your vehicle is fifty years old, it lacks the technology that more recent vehicles have that makes them run better, last longer, and get better gas mileage.
I can't think of a 2021 vehicle that will be drivable in 50 years. They are not built to be fixable; necessary electronics goes out of production. My '51 one ton gets the same gas milage as my 2012 3/4 ton.
If your vehicle is fifty years old . . . It's not really possible to "restore" . . . if for no other reason than you can't find parts.
I can get new manufacturered, NOS, repaired, and salvage parts for my 1951 Dodge; I could build a whole vehicle out of acquired parts. I got rid of a decent 1997 Dodge because the electronic modules were becoming hard to obtain.