The aluminium plate in one of your pictures is a 'repair' plate.
So it appears mine was 'repaired' at 13Km and yours was at 19km (or 10 because someone wasn't too handy with the number stamps).
Whether that was really 'repaired' or whether it was when it was checked through the workshop and any intervening modifications carried out I'm not sure.
The seats in the back mean it was probably a GS (General Service) although anything can be changed around on a Land Rover (as mentioned).
As to seatbelts, I'm not sure about NSW. In VIC a lap/sash belt is needed for the outer seats and a lap belt for the centre from 1/1/71. The sideways facing seats probably need a lap belt (VicRoads data sheet isn't clear).
The decision you have now is whether to get it back to Military spec. or leave it as is.
Mine is fairly original (still has Dymo Tape warning on the dash etc.) if you need any pictures let me know or the thread is here
2a GS Refurb ARN 178-334
It's been a 'long term' project.......
Colin