As Julian notes, early frames have a sheet metal brace at the lower end of the headstock. Is this in place and undamaged.? The number should be above this brace. I believe on later frames this brace extends almost to the top of the headstock and suppose this would be where the frame number is found, on the brace. I can see the remains of the brace on one of the pictures, below the cleaned off tube. Anyone got a late frame to check the number location?
There are a few minor details which would indicate to me that the machine is not entirely original. That's not to say its not what it purports to be, just that it is not quite correct.
Front and rear mudguards are not contemporary. Rear is the later "arrowhead stay" type, 1960 onwards. Front mudguard and fork ends are an earlier version with the two bolt rear stay mounting to the blade.
Looks to have an auto magneto. I would expect a manual type on a sporting model. The nacelle side flashes are absent. Late models have the choke lever under the saddle nose. Speedo cable past its best, and certainly not right. Also, in my estimation, unusual to have a single petrol tap. Twin taps and a centre banjo are more practical.
Don't run without an air filter, its absence is detrimental to pistons, bores and carb mixture settings. Like Julian says, a little more explaining to be done by the vendor.
Swarfy
