Dave,Thanks for the very kind offer Chaztuna, I'll try a few more sources here first including lawnmower repair outfits, good suggestion
Thanks for the info Chaz, British fuel tap fittings aren't usually barbed as they consist of a separate spigot and nut, but you can get barbed type spigots, although I suspect the id of the spigot is probably a bit smaller as the nut has to fit over the barbs, if that makes sense. Anyway, probably not an issue as that isn't usually a pinchpoint in the fuel delivery.FYI, on a gravity feed fuel system, like your Bonneville, Tygon tubing will not require clamps, providing that the male fittings are barbed. The Amal fuel filter housings have barbs. Not sure if the 1970 petcock [aka fuel tap] fitting is barbed. I'd have to look at my 1970 parts catalog.