Another recent acquisition to my lineup of Canadian Mk II's 1941 dated Mk II as produced by General Steel Wares (G.S.W.) steel lot batch N it is sporting a 41 dated VMC liner in a size of 7 1/4 flashed with the letter P to the front of the helmet body these particular flashed examples are quite rare and almost never appear in the market place.
It is thought for the most part that the letter P was used to represent auxiliary members serving with Police Departments as apposed to the regulation helmets which sported the word Police stenciled to the front this of course would make for easier Identification of auxiliary members from a far.
I have as well posted an image of one of my Canadian issued Police helmets to illustrate the difference and for comparative purposes of the flash.
IMO this particular Mk II is an X-Wardens helmet which is apparent from the front as it would appear that there was a Capital W removed from the helmet body and then re-stenciled over.