The lack of parts would obviously kill the late model ones off fairly shortly.
But even if parts are available, they'll still be extinct in 10 years or so (the later model ones). The parts (if available) won't be inexpensive, the labor will be not-so-easy to find and won't be cheap, either. And there just isn't going to be a huge enthusiast interest in keeping something like this on the road, in any significant numbers:
