I have found one other transfer like this on a Canadian Mk.II. Below is a comparison of the two decals next to each other, but the other appears to have been placed on the front of that helmet, not the left side as this one. Though on the other helmet I cannot see the rivets on the sides, so is it on the front or the side?
https://www.milsurps.com/showthread.php?t=60966
Comparing them, they look like the same die / manufacture run, same decal.