Yes I have more information on these cars but most is duplication. If it is really important I can put all the info together in a timeline (GM did change the vehicle orders) a couple times.

The ute IXD-457 was already in the GM fleet as the Sales Departments car, before a requisition was placed by marketing to have it used for the press fleet.
Interestingly again the panel van was to be delivered to the press fleet test with 1500-2000km on the clock for 'run in' and then serviced.