I was able to get one from Allspars in Plymouth recently, from stock. They had a good supply ‘off the shelf’. I have been told however they are no longer permitted to supply and that in future you have to purchase through the Builders/Porters. I do not know the facts, I merely report what I have been told by a source whose living will be affected if such restrictive practice is what we must expect for the future.
It will be interesting to watch the price and availability of masts/booms/rudders etc.