While I am not certain about the Second World War, I do know in modern times that depending on the Regiment, Canadiansoldiers are notorious for ignoring inconvenient equipment regulations. During my time, it became common to hot-rod your own gear to make up for issue shortfalls and equipment shortcomings. I am sure this sort of thing will prove very frustrating to collectors and historians alike in the coming years.
For example, the issued load bearing vest had pouches for 4 magazines and one on the rifle, but our combat load evolved to issue 10 magazines minimum, where did the other 5 magazines go?
When it came to weapons we generally left the internals alone as there was no need to mess with them, but beyond that, if it could be tinkered with using a multi-tool or stuff found in the vehicle toolboxes, it got tinkered with.