1911 King George V Uniface Lead Trial Strike

I'd be skeptical of that claim.
Are there designer initials on the truncation of the bust?
It does not look like any Mackennal portrait and unlikely a trial piece would be struck without an authorised portrait.
I doubt that the mint received from London any portraits to work with other than the two by Mackennal which the King had approved.
The sovereign was in use pretty much world wide, was legal tender in a number of countries including Canada, and was minted in a few different countries.
Why would anyone consider a separate Canadian minted design?
It is highly unlikely that any major change in design would be contemplated.
An almost universally recognized and accepted coin.
If it ain't broken don't fix it.

looks more like a dragon slayer sovereign (engraver's initials on the reverse which is still missing on this "trial strike") than a Canadian strike.

perhaps the engraver doesn't "sign" his/her work until approved/goes into production?

http://www.cruzis-coins.com/sovs/1911l.html

Last week at the coin store with the first XRF, most of the employees were , never seen such an item and the person who did the XRF just said it's pure lead. Today round two XRF 99.92 lead, .016 copper, .180 silver, .023 rhodium, .019 palladium, .041 platinum and the edges looks like they have been nipped off, no collar, any info thanks in advance.