I think that trying to think availability of parts 10 years ahead is not realistic. In 2013 I bought my M3W, fitted with a low volume S&S engine. I probably wouldn't have bought it with a "high volume" Harley (even if MMC could have got them). I don't know why but at the time the X-Wedge seemed more attractive to the overall package.
As original manufacturers disappear others, usually materialise. If the car is worth £30,000 upwards, there will always be someone who will be sorting the supply problem...or a bunch of owners, to get their cars back on the road. You don't just lay a M3W up for the lack of a "widget". Look at the MTWC, they produce those stopper items for the older Morgan 3 Wheelers for that reason. It's not actually happened with the M3W yet but they are there if it does. If there is a demand, even a small one, someone will fill it. That may be at a price but £210 for a little skinny tyre is not cheap now, so you will be familiar with high prices for your Super 3 parts in 10 years time.
