I have two WW1 SMLE rifles with Canadian markings. Both are different in where the marks are and size of stamp.
One is N marked on the metal, LSA made. I'm thinking it was probably British navy use, saw lots of use as it was rebarreled in 1917, made in 1915. Wasn't FTR marked, still has cutoff plate and what's left of volley sights.
Other is BSA made in 1918, from the serial number it was early made or late production that may have never seen use in the war. They rolled serial numbers back after a certain amount of production. It has C marks on stock and metal. It's definitely been shot lots by how much the bolt head rotates past where it should, has a pin with number on it stuck into the stock. Number for a rack somewhere along it life?
Whether or not they saw any Canadian use in the war is a mystery. They were in Canadian service at some point in time.