Thanks for the bad news

As you can probably tell, I'm not especially mechanically minded, and I'm beginning to wonder if I can face the hassle. I've found the sprocket and splined driver at my usual supplier, SJS (I'm in Europe), but I can't find the dust cap, spacers and circlip you mention.

In case you have a moment, this is their SA section:
http://www.sjscycles.co.uk/sturmey-a...key=cat&page=1