Update.
I have called a number of prominent auto trimmers, even traced back to trimmer suppliers(dale's and Nolans) but to no avail.I did get a response from a bloke in Perth with a HZ sandman with the same pattern, but in red and orange, so I can only say that there must have been more, but from where, I don't know yet. It has been suggested it may have been a dealer's special accessory pack for a model run out promo, so I can only add that this particular example (of a sandman HX) was a late HX Pagewood build, sold through Muirs in Sydney.It's also possible that rear carpet, driving lights and after market AC may have also been part of a run-out or promo package. I f anyone has any clues, or knows where I might get it re-proed, any help would be greatly appreciated. It is a woven polyester fabric, and was stitched over the vinyl centre panel during manufacture.
As for historical records,(for this website) I will post any more findings.