Is this yours, DJacey?
I've known the bodyshell for a long time. It was first imported to the UK by Fourways Engineering - at least 30 years ago - to be used in the build-up of a race car. It was Fourways who carried out the reversible LHD to RHD conversion, but then the project was shelved and put into storage. I first saw it in person at least 20 years ago.
The story linking it to Bob Sharp Racing in the USA is very likely true. I believe this bodyshell was picked off the production line to be sent to Bob Sharp - as a spare in case of crash damage to his race car(s) - in late 1973 during the transition from '240Z' to '260Z' and the low chassis number is very close to those in other Bob Sharp '260Z' cars. Geoff Jackson of Fourways told me that they bought the bodyshell on the east coast of the USA from a former member of Bob Sharp's team.
There's no V5 with the bodyshell as it was never built up into a car and (being intended as a race car) never registered in the USA, so there was no 'title' and it was imported to the UK as spare parts with no intention to use it on the road.