Early W utes and vans have 2 x different rear finishes listed, for Kingswood utes and all Belmonts (which may mean wagon too):

"Colourflek" Astro Grey 611-14224 or
Grey Vynacote 599-15160.

I have the formula for 599-15160:

Tinter - Setting
34178 - 0
11999 - 80
00740 - 158
05440 - 165
00744 - 168
01012 - 500