I can understand the concern about the possibility of making old poorly tuned non cat cars into daily drivers, no matter where one lives.
Seems like a good acceptable self-restricting compromise for everybody would be simply require there be less than a 10? year old car registered, licensed, and insured to same person same address as the historic car.
Nobody will want to make a daily driver out of an old car when they have an under 10-year-old modern car insured sitting in the driveway with the cost of fuel, etc.
I believe that is often the requirement anyway for collector insurance anyway.
You want to really reduce air pollution incrementally everywhere, do away with fast food window drive thru lines, or at the least add a window surcharge, people need the exercise anyway, then enforce no rubbernecking laws, how, I have no idea.

We could also mandate drafting at anything over 50mph? Oh wait, they already are doing that.