Terry,
I think the answer is that each of the items mentioned was a "standard". The wheels used on CMP were basically to War Office (UK) design - standardized. The hubs the wheels were mounted on were a Canadian design so used "standard" threads. Left hand threads on the left side was common practice at the time- "standard".
If you are suggesting there should be a single global standard for threads and other components, you will have to get the USA to change to metric, and wait for all existing SAE threaded items to work their way out of existence.
In other words, don't rush to get rid of your inch wrenches...
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