
Even in my small country there are already 2 flying replicas I know of, so you are most probably right when you think the number of replicas is close to the number of DR.Is originally built. For a period when photography was still something new an amazing amount of pictures were taken from the Fokker Dr.1.
Personally I think the aircraft would have been forgotten already a long time when the guy above hadn't died in one. Manfred von Richthofen was made a myth by propaganda already during his life time. After his death people only continued to add to the story until he had turned into something which was completely invented and had no nothing to do with the real person von Richthofen.
But ike Mikael Carson said in one of the interviews; when you build a replica it should be something people recognise. Well everybody has heard of the Red Baron, although most people think it is a guy with a big moustache and a pike on his helmet

The myth around the red Baron leads to weird things. Like all the bad guys in the movie Flyboys fly in a red Fokker, while in reality even most of the 7 (!) different DR.Is van Richthofen flew, were painted only partly red!
Fantasising about von Richthofen did also lead to the weird idea that some dogs can fly on top of their doghouse.......
Cheers,
Huub