Based on the colour scheme I suspect this may be and ex Navy mini van - I know a lot were used in the dockyard in Sydney but not sure where else.
A similar colour to the Navy sky blue was offered as a standard Mini colour but in vans they generally did not have a white roof as per Navy colours.
Unfortunately Navy vehicles were Z plated Commonwealth vehicles without any other identifying plates like Army vehicles. So may not be Navy but the colour scheme is pretty unique.
https://www.ebay.com.au/itm/Jay-blue-1968-Morris-minivan/152902294731?hash=item2399afdccb:g:M2sAAOSwtIdafsCJ
