I am very interested to contact other people with a real interest in the B18. I have owned mine for over twenty years. I also have many photos that I am willing to share should there be a need. I can also machine replica parts if anyone can't obtain originals.
I have a B18 as well. I just finished repairing the central stand. I have machined the hole round again and made a new bush. If you were to make parts I would like to have spring attachment bracket. Mine is pretty bad and I was considering machining one from a flat strip.
I bought my B18 with a lot of history. I even have an original picture from one of the earlier owners on holiday with his B18.