I forgot to say how envious i am of your Excelsior, absolutely beautiful. Regarding the special, we simply bought the motor off ebay and collected appropiate parts at swapmeets. We have no idea what brand of bike it originally came off. We lucked out with the 4 speed burman box but it had a wrecked mainshaft so had a complete new one made from scratch! I think the motor probably came from an OK Supreme as they had the dry sump motor fitted as well as this particular burman box. Has your third downtube been sweated on or migged, arc etc?By the way, Excelsior, OK Supreme and Levis are my favourite looking bikes.