I am a great lover of British bikes. Recently I visited my old parental house where in the barn I found the remains of a Norton flat tank motorcycle in very rusty condition; it used to be my grandfather's bike. The frame number is 331xx and the engine number is 404xx.
Simon: "It is a Model 2. Engine and frame numbers match. Originally fitted with B and B carb., 26 x 3.25 tyres, Druid forks, and CS gearbox number 100232. Despatched on 26/5/28. The dealer's name is very hard to read but it was probably an export merchant dealing with India and it looks like Diodar. Note the clutch is from a later model and the crankshaft is missing."