Mmmm, I think that is going to be a tough call - same happened to me many many years ago, so whenever I do the basic checks under the bonnet, I always gave the wing nuts on the Webers a tweak. I think they were indeed unique to the 34/35's. You could try Paul Marshall on here - send him a p.m. Cheers. G.
The jet cover and therefore castleated spacer fell off my car on saturday. Does anyone have one? Weber dont seen to list this part as it seems unique to rootes. Any help finding one would be very much appreciated.