If you need slide diaphragms for your constant velocity carbs:
NRP motorcycle carburettor repair specialist
Essentially, they take your old core slide pistons and fit new rubber diaphragms to them if you are uncomfortable about doing this job yourself. Tell Andy, the owner, I sent you. They are fairly reasonable and when I find myself needing a new diaphragm that I can't buy directly from my suppliers or is not available, I turn to NRP. Their shipping is quick and reasonable. Unfortunately, the US $ has slipped against almost all the major currencies so it makes dealing with overseas companies more expensive than it used to be but their prices are still reasonable! wg