Here in South Australia the requirement for historic rego is more-or-less originality and pre-1978 build, and full rego requires the machine to meet the design rules for the build date, so we don't see bikes like this. It's a problem with things like the repro strap-tank Harleys (Timeless I think they were called) - built in the 2000s to a 1910-ish design - as there is no possibility of them taking to the road.
Leon