Im afraid 2+2 body panels are rare in the Uk, im not aware of anyone who does repair panels for the area you require, most would be made from scratch by whoever is doing the work!
The rear lower corners we get from MSA in USA are now without the bumper indent to suit later 280Z models over there. I think that they would work for 2+2 also:
We have a manufacturer in the UK who will produce several 2+2 panels to order:
Sill return repair (dog-leg)
Lower door skin
Tailgate repair skin, lock face and corners
Rear upper (slam) panel
Rear lower valence