To be or not to be a HZ Sandman ute???

[Pritch72]

Hello All,
Its great to be a part of a group of like minded Holden devotees... ��
I could use some help getting to the bottom of a mystery ute I'm interested in buying.
It presents as a '78 HZ rolling shell. The body has most of the original paint revolved, however the colour under the interior roof, dash and cowl area is Valencia Orange. All three tags are with the ute, however the colour code suggests it should be Jasmine Yellow... Now this is where the mystery deepens....
I understand that one of the ways to determine the authenticity is the codes xx7 and xu3.
However bothe the tag and chassis have been 'very roughly' stamped with the code 'xx8'... Also the seating capacity has been re stamped from 3 to 2.
I'm wondering if this is a 'factory fix' of some kind???
Codes are:
8M80RHL405913Z
Model: HZ8WM80 XX8
Body: 405913-A
Trim: 1927-67V
Paint: 568-30518
Eng: L32 Trans: M20 RRAxle GU4
GVM: 2155
Chassis No: 40120ARXX8
Build Date: 12/78

Any help with shedding some light on this mystery would be fantastic... ��