There were a couple of myths about Corse bodywork.
The flat roof spoiler which Andrew mentions was only as a result of laziness on assembling the two half's. Upper and lower. I made an acceptably curved spoiler from the same moulds while they were in my charge.
The other myth was about the concave roof shape which again was only on some cars when the centre section mould had been stored with something on top of it prior to use. The mould was flexible! If you turned it upside down and put a bag of sand inside it popped back to the correct shape.
There were two sets of Corse moulds. The original ones, some of which appeared to be of Allora vintage, and a further set produced by an outfit in Oxfordshire. That second set had supposedly been refined, but the moulds were as floppy as a very floppy thing, and coupled with some very resin rich thick laying up the panel quality (Napiersport) was very hit and miss.
The original moulds still exist and are in private ownership. The second set were sold to France and are probably best forgotten about.
The LB panels are light years ahead of Corse/Allora stuff.