Godet no longer does such ‘new old’ builds. The only bikes they do from now on are new and registered as such.
To do this they have to have left hand gearchange, indicators, mirrors. So they clearly have to conform to some rules, but I’m not at all sure what and how.
It might be a situation where if the production is under 50 per year, for example, the rules are relaxed.
A friend in Norway who built a lovely one off Egli Vincent ( 10 year project, every spare moment) was denied registration.
The licensing department figured out it was a new build .They required full crash testing and engineering data as would be provided with a new Volvo model.
After you crash test and destroy ten you might get to build one for keeps, we'll see!