As it is Acacia Ridge build it has to have XU3 stamped on the BODY plate to make it a Sandman. Without it, it is not a Sandman. I think I have seen this one before, the PSN should be 444486, and recorded it as not a Sandman I may have misread the second last digit of the PSN, possibly the last as I remember the plates being hard to read. Stamping mistakes like the UU on utility are reasonably common. Missing the special vehicle package code has been known to occur but very rare, non-existant outside of HQ in my experience. The reason is these were stamped before the car was built at Acacia Ridge, even before it was painted. Whereas the ADR plate was stamped on the run whilst the car was on the end of the assembly line. Unfortunately you'll never know if it was one, XU3 HX and HZ utes are almost impossible to pick from a normal Holden ute, and all the stuff you have quoted (N66 rims, U17 dash, M20 4spd, sports steering wheel, XS6 buckets) were common options on HZ Holden utes. Only paint blackouts will help you. But not worth restoring as a Sandman as it'll neveer be recognised as one because of the lack of the XU3 code.