My sprocket and hub was changed at about 6,000 km just before warranty expired last month (it was making a terrible shrieking noise, although it hadn't actually broken) and the dealer did it as a warranty item, but I don't think they have been paid by Morgan. The later hub and sprocket replaced the earlier one.
The whole thing was odd as the dealer initially told me that they had been given clearance to do it as a warranty item (after the car was serviced and the noise had got a lot worse!) but when the job was done a few weeks later Morgan wouldn't cover it.
Sounds a bit dodgy and I expect I only had it done "free of charge" as I have a long record with the dealer and 2 Mogs serviced there regularly.
It doesn't sound as though the factory is being fair but I also expect there's an understanding between dealers and the factory that all parties need to bear some of the warranty pain as the company could otherwise go under. I've been quiet lucky with my car otherwise and had relatively few problems to date, but only 6,000 km so more will probably follow and I am out of warranty!
Like so many of us, I certainly didn't expect this sort of fight and major servicing expense (my services and 'replacements' - wishbones, Comfort steering) have so far cost £1300 or about E1500 over 4,000 mile which makes the 3W by far the most expensive car I have had in terms of running costs...