How to remove a cab 13?

[Grant Bowker]

The simplest explanation I can think of for the conflicting plates of is that parts have been exchanged between trucks. I don't have the full list of the differences between Australian and Canadian manufactured cabs but based on the ventilators, suspect that at least part of your cab is Australian.

When I mentioned the rear of the frame, it was because there might be holes or paint shadows suggesting either mounts for the tipper body or a winch to give an idea what the truck might originally have been.

I don't know enough about the number on the "model" line of the Canadian plate to use that as a starting point for further speculation/fact.
That style Canadian plate is more typically found on early production than late. I have certainly seen them on cab 13 trucks but in one case wonder if all previous owners have been honest due to the location of the plate.