As Sean says, no way of knowing.

I reckon the ones you see the least of for sale are HQ/J/X/Z utes.

HQ had the shortest build time so they would have to be the rarest. HQ and HJ are the oldest and were also the less obvious over the years so that may also contribute to their demise more so than HX and HZ.

I reckon that during the 90's most of my generation would not have even known there was a HQ and HJ Sandman. HX and HZ were a bit hard to miss.
I know one HQ sandman van bit the dust by a tenant we had living in the cottage here. Off came the roof and it had a front cut put on from a hz ute and voila..... hq sandman van became a HZ ute. In 1995 a HQ sandman van was worth about $500 and any v8 HZ ute was worth about $5000.
I think we all need to bear that in mind when trying to identify a Sandman from its body shell.