Possibly. There were 3 x assembly plants making HQ Sandman vans, and 4 x making utes. So who knows?

After further thinking (and without looking for evidence) I reckon a first pass theory might be that the HQ cars that came standard with console shift by 1/74 all had retractable seat belts as standard. Meaning the few odd ones out that got consoles but didn't have retractables (basically HQ Sandman) suffered without somewhere to put the buckles. One way to tell maybe is to look at the grain on the consoles. Early HQ consoles should be a Roebuck style, pebble grain vinyl looking plastic. Later ones may show the Caribou style (long grain) vinyl seen from 1/73 onwards on all HQ vinyl. Sound like a good place to start? If the grain didn't change with the trim in HQ, then maybe GMH did use up old stock on HQ Sandman, and these ran out earlier at some plants than others?? Only guessing here.