Sorry for this late reply – I have been laid slightly low with food poisoning, and hadn’t looked at the website since yesterday morning.
Ian Parsons, our registrar, advised me that this is a matching numbers machine. I’ve attached a scan of the buff log issued in the mid 1950s which shows the same numbers as today. As far as I can see it is remarkably original – the saddle has clearly been re-upholstered at some point but almost all the other controls and fitments appear correct and appropriate to the year. It appears never to have been restored, extraordinarily the leathercloth tank covering still bears its Scott limit gauge stamping.