I would keep it original if all possible.  In my mind that is the charm of the old school vehicles. When you start changing and updating parts it will eventually turn into a nightmare for someone down the road. I have a 1924 Ford Model T coupe that is almost all original. They are only original once.  I guess it would make a difference if the driver wants to tour long distances but if it is just going to car shows and parades I would certainly consider keeping original.