I am lucky enough to have an original fresh air door assembly that the door actually opens and closes. Also have 3 or 4 that when I have time will do a repair similar to what you did and put them back in service for someone else to use.
I suspect if a car was treated nicely to a garage or carport at least for most of it's life the originals would be good. Most of these poor old babies don't get that kind of treatment.
