In case you have not noticed, the pound is now only $1.47. If you need parts for your Norton, buy British. You will save a good bit of change even with shipping. I just saved $30 on some fuel petcocks.
On the transmission I rebuilt a while ago there was a ton of savings by ordering from England. Although I did buy a complete set of gears and a mainshaft with all the bushings and seals, And that was before the exchange rate changed. But the bigger the order the better the savings. Chuck.