Well, I've made a bit of progress with this.
Got some rear shocks thanks to Lowry in Germany
Also a friend of mine managed to find a NIP Bosscat (I think) slipper
Have started taking it apart and found that the top deck is actually cracked in 3 places
It screws down flat when built and for on the shelf I wouldn't be worried about it but if I'm going to run it then it throws a bit of a spanner in the works. Especially as it's black and another top deck won't match the chassis now...