Hello again from England -
6 months on, after your help in identification, thought you might be interested in progress.
Obviously it had been mouldering for decades, and I landed up with little more than the frame, handlebars and some questionable bits and pieces.
With a bit of general mucking-about, machining, special metric/imperial bearing searching .......... usual stuff, it's up and running using kart parts.
I went a bit mad and put an electric-start clone 160 motor on it, plus an OldMiniBikes Warehouse clutch brake and a 5 quid seat off eBay.
It's probably lethal on kart slicks ......... and the gearing is too tall, but hey, all things to play with in the future.
Possibly may have to sell it (too many toys), so anybody over here wanna buy it - message me. It'll be a good few hundred quid.
Or I may put it in the house as an ornament :shrug:
More pics or info just ask.