front guards

[Innuendo]

thank you for that, so you couldn't even get them as an optional extra on HX and HZ?

Anything maybe possible but unlikely. This would need a SPO to be approved and unless you have the SPO paper as proof, you prove nothing!
Ordering from a Holden Dealership and having the Sandman delivered with fluted guards is also a possibility and a more likely scenario. But this would be the Dealership's doing not Holden.
Most likely is that the guards were done after the new car sale at some time.