Ooh! I like that. We used to be able to get Dominion ammo here in the UK, blue and yellow boxes IIRC. They loaded .455 Webley until quite late, only I think they called it .455 Colt.
A friend gave me a few of these Dominion rounds, which mostly failed to fire. The date code proved to be for 1951... I have pulled the bullets from the rest for reloading with fresh powder. The powder in the original rounds had degraded and seemed 'wet' and sticky.
CIL was known in Canada for providing relatively affordable and good ammunition. In European metric calibers CIL provided generally stiffer loads than was available from the American manufacturers. My only experience shooting CIL 6.5 M-S loads was in the late 80's or early 90's hunting Blacktail Deer on an island off the west coast of Canada. With a nice M-S 1903 fullstock carbine I missed a very easy offhand shot at a Blacktail standing broadside at less than 50 yards.(I switched to some other brand of ammo and shot a deer later that same day.) Back home at a rifle range I found that some of the CIL bullets (not all) were tumbling out and hitting the paper sideways nowhere near the point of aim. They were ancient and I should not have taken them hunting. I don't know when CIL stopped making ammo, but it seems like a long time ago now.