That’ all very well Dave but noise in the cabin is part of owning a classic, or should be as is heat and cold.
Regarding heat in the summer heat shielding is OK if you never drive your cars in the winter but I do (I have 3). So in my opinion open the windscreen and door windows in the summer if necessary and during the winter give the rear passengers a blanket (again these were always found in cars in the 40’s and 50’s). Not every one can find a period heater.