I think I will go for maddog34's proposal. In the end it is not imperative that the bike has originial parts. I will probably look for a second hand rear wheel and do a hub swap or use the second hand wheel. The braking surface of this rim is still very nice, so I would like to keep it if the hub flanges match.
Thanks for the insight on Sachs Duragrouch and dedhed , looking at some of their stuff confirms that it is too much trouble trying to find a replacement for this freehub body. The link posted by duragrouch is the closest match and the only one with 9 external splines.