Quoting: a91_formula
Apparently it is a hardtop with the Y82 package, which is a t-top package!.
I read that thread too during my investigation hence why I came to the assumption it's had a new roof at some time.
I am a bit dubious though as I did read somewhere that dealers sometimes selected the wrong option code when oredering and also the car came into the country in 79 when it was just two years old, so if it has had a new roof it was probably done here.
Either way it is still a special edition and I'm pretty chuffed.