Thanx Shrek.
Ive been reading up on it a fair bit today and the general consensus is that its reversable with the right strengthening of the traps and Rhomboids, along with A LOT of stretching of the pecks and front delts.
Havent really gained an idea of how long it will take, but i assume because its been bad for years, it may take years to fix.
At the moment i feel people think i look good front on, but when they see me side on its terrible. I train hard but only take my shirt off when absolutely necessary. I'd love a reasonably straight back.