The mufflers aren't JAWA as they should be fish tailed.
Some pattern parts are available through MzB of Germany or from Old Timerteile Clements. Were talking parts like brand new generators, exhausts, etc.
I know someone who rides one on the road nearly every day and has been for the past 20 years or so, since he brought it back from Holland.
It is in the same ratty condition as yours, does about 50 MPH tops but still runs smoothly. He rides it to motorcycle rallies all over the UK. He's also over 6' 6" tall so must be a bot of a masochist to ride hundreds of miles a day for hours on end on such a small bike.