Hi Fred, I think that George Silk used to make them many years ago, but nothing even vaguely recent. If I was really stuck for an adaptor I would fabricate one using steel. A piece of curved exhaust pipe of the correct diameter would enable you to fit a carburettor at a shallower angle, to suit the angle of the float chamber fitted to the carb., as only the Scott takes a carb at a 38 degree angle !
I have had a few three bolt flanges laser cut from 6mm steel and some 2″ two bolt flanges, and I made my own to fit a more normal carb, send a PM if I can help
Ps just fitted a new two stroke concentric to the 49 flyer I am reserecting, works very well, not for the purist though, I like a bike to work!!