Well, the Nova/Sterling was sold under many different names in many international markets.
Each sales market called their version a different name, as well as implemented various minor styling adjustments.
The 'Nova' was the original created in the UK.
The car was sold in the US as the 'Sterling'.
The Sterling spawned two other major variants in the US - the Sebring and Cimbria, each of those with several subdivisions (such as Nereia, Cimbria SS, Sebring Turbo, Stering Sovran, and others).
The Nova was sold in Canada as the 'Bernardi'.
The Nova was sold in Australia as the 'Eureka'.
The Nova was sold in South Africa as the 'Eagle'.
The Nova was sold in New Zealand as the 'Scorpion' or 'Spider'.
The Nova was sold in Italy as the 'Puma'.
The Nova was sold in France as the 'Defi'.
The Nova was sold in Germany as the 'Ledl'.
The Nova even made it to several other African nations where it was marketed as the 'Tarantula'.
Later, after the original Nova company changed hands a couple times and was sold under the name 'Eagle SS' in the UK.
Back in the UK, the original Nova went through a number of design iterations or Series. Each Series made adjustments to the original Nova to make it easier to build / drive / live with / look at / etc.
The rear end treatment that you've shown in this picture is from a Nova 'Series 3' which was actually just a kit-for-a-kit package marketed to existing owners of earlier Novas who wanted a more modern tail treatment. The new package could be implemented on any Nova/Sterling/Whatever car built since the inception in 1971.
Of course, the very nature of a 'kit' car is such that any enterprising purchaser could buy a kit, assemble it per the instructions, then modify it as they sought fit and their skills permitted. Of course, then they could call it whatever they wanted.
