HJ had silver fascia. I think you could get black fascia as well, somewhere before HZ, not real sure. The 2 idiot lights above the steering column, one is hi-beam & other handbrake light. HX -on had two red idiot lights for hand brake & brake fail. Early HJ Speedos were only 5 digits on odometer, I think that changed to 6 during HJ. Wiring harness for HJ is different cos of idiot lights. Little symbols in gauges, (fuel, temp etc) are different plus the segment lines in Speedo & tacho. A lot of HJ facias have the centre vent hole blocked, unless a/con.
I'm sure there would be more, that's all I can think of

Cheers
Max