I cannot answer for the PR from the Museum. It seems to be a matter of luck as to who has had a good or bad experience. Of course I know them well, they do not suffer fools gladly and have put themselves under enormous pressure by moving several businesses, cars, house etc from one place to an unfinished and unstarted place with no other way of making money. So you were talking to busy people.
I say fools, this includes a wide range of what to some count as non-foolish enquiry. In this case you had a car they had already discussed with the previous buyer. I could tell you without reference that you would get little information as I suspect this had revolved round the mix up over the lotting. Both Mike and I have been dealers. You just know when you reach a point where you are not getting any merit from a topic so it gets blanked otherwise you just revisit the same thing again and again, which we are doing now. To be blunt, what benefit is it for Mike talking about this? In most cases only negative. I can see where he is coming from and I am exactly the same when people question me over something I have no wish to expand on or want information I do not wish to disseminate for some reason of my own. For all we know the shell you have was subject to an illegal number plate sale and was passed on with a deed of trust to obscure its ID, perhaps it should have been scrapped. I used to buy from number plate dealers and took cars that had to be broken up as part of the deal. I did so, even recycling some very good cars in the process. To continue trade trust has to be maintained. So there are cars out there that are bitsas but that is better than scrapping them for their weight. Sadly the anoraks will not accept this and pick at the scabs and that has resulted in quite a few cars being destroyed by those that do have something to hide. Blame who you like but this is reality. I can list some I attempted to liberate but will not. You would cry as there were rarities. That is the nub of providing information, once out its Pandora time be it private, register or business. Unfortunately thanks to our stupid Government system the owner of a car is not empowered to have access to the history of that vehicle nor a title deed proving ownership. Not only that they conspired to create a trade in IDs. Until that changes you are hostage to a variety of problems in gaining information about a vehicle not aided by the Government encouraging the Councils to throw the ownership details they did have away. How jolly convenient. You want to gripe at someone have a go at those silly ******s.
Prinz.
Clutch has to be about as easy as a clutch change can be and is done in situ if you want.
Brake cylinders I used fitted quite a few other cars at the time so not sure about that factoid. Seem to recall rear Audi 80/100 and VW Golf, of course these were really NSU inspired so no great surprise there. Used to be £25 a throw from a factors. Certainly seal kits are about and they might hone up.
I found the NSU club very disorganised for parts. They had an old leaking shed full of stuff but little idea what is in it. They were traditionally slow to respond. I ended up buying 4 tons of ex dealer stock and traded with Mellman? in Germany or sourced at Mannhiem as it was cheaper and quicker stock and upon getting out of NSU I sold it well - the club failing to purchase the cages despite a low price being asked. This was some 10 to 15 years ago so things might have changed but I found the Club had a lot of inertia to anyone who was about it and jealous of activity, like finding Sport Prinz and Spyder, as it made them less rare. A shame as the cars a brilliant with annoying faults
Rear drum, this has a habit of being loose. You need to check out the fit and get it clean and then a good clamp on it with a good lockplate. You can tell if it is not home as it will not roll correctly normally, being eccentric, so look for run out or there will be an audible knock as it is loose. Do not confuse brake snatch as run out. The drums go oval as applying the handbrake on hot ali/steel insert drums sets up a strain. If you have round rear drums you are a lucky fellow! It is always worth cleaning and lubing the brake adjusters. These are a weak design.