I take it you mean't 11-75 not 11-95. 11-75 is not late for HJ as the HJ run finished at the end of June 76.

Melbourne cars would have never received a Brisbane chassis and a Brisbane built body would not have gone to Melbourne for assembly. Even if a late run car got a newer model chassis it wouldn't be stamped with the newer model number.... IE HX stamped chassis on a HJ plated car.