I'm sure the intent her is to keep it ORIGINAL......but I've seen some photo's taken of original stuff and the good artist of today can duplicate it pretty dang good. In the end the choice is yours. Its only original once so you may want to keep the door and replace it?
We have a bolter here who has a "gallery" of old Door art. I think it's woody that does it........I'm sure someone here has that link.
EDIT: here is the link. Enjoy.
http://www.pbase.com/czechman/door_art