Possible HJ Sandman

[GTS]

2 seater, 1950GVW,

That'll do it

full head lining. as is holes for interior light switches,

That'll do it

The worrying parts are
Long tailgate hinges, Rear taillight surrounds not painted, Vinal floor present behind the seats as well as black loop pile carpet,

A hit up the rrs could discount the hinges....a lot of folk put chrome tail light surrounds on vans way back when, because they look better and how long will a 35 year old carpet last..really.

holden badge in the middle of the tailgate.

Right where it should be on a HJ

The trim is 1887-19V. There is one black passenger seat present and the hoodlining seems to be a off white colour.

19V = Black trim and, from what I've read, black trim vans had a chamois (off white) hoodlining...so that'll do it.

Should there be air vents in the door jams behind the doors?

Yes.

And if it has the "toothed"strip above the tailgate for the the hoodling to mount to, as well as the side strips for same, then I (as a novice) would be prepared to say you have a genuine Sandman....although I stand to be corrected