Hi Graeme,
Yeah it is a real model - the compliance date is 4/77. Its a 1976 model - and it does have a bigger seat and thats about all.
The sticker just goes over a previous model's tank. And you can actually sit on that seat!
Its much the same concept as the Bultaco Alpina, but I think Bultaco sold a lot more of them.
Cheers,
Mark