If you put the ID plate details here, of PM them to me i'll try to help.

I have 3 x HJ and 5 x HX Sandman in 1894 (Antelope metallic), one of the HJ's is Fawn (64V) trim. So not a very common combination or colour in HJ.

Whilst being L31 M41 make is a very good possibility of a Sandman it doesn't mean it is. The good thing is if it is originally console shift it is a Holden Sandman van. If it was column shift it is a Holden van.

I don't think the trim matters too much, do it as you please. It isn't that expensive to change it back relative to what a properly restored L31 M41 Sandman van would be worth. Antelope would probably look best with 19V (black) trim a sthat is the stripe colour if they were fitted. 19V and 60A (beige) were the recommended trims for Antelope metallic. 64V was not recommended.