When I lived in Newfoundland, first on Fogo Island, then Lewisporte in Notre Dame Bay, I saw in total about half a dozen Newfoundland-marked Lee-Enfields.
All the rifles I saw were Mark III or Mark III*.
In each case,the only marking was on the Butt Marking Disc, where a Newfoundland rifle will be marked NFLD. Of the rifles I saw, only TWO had not been chopped. One of those was in a Museum (LSA-1915) and the other an Enfield which still was in the hands of the man who liberated it personally in 1919.
You MIGHT have a chance to get an NFLD-marked rifle if you talk REALLY nice to some of the guys who actually live IN Newfoundland. Likely it will have been chopped for a Moose gun, but THAT is repairable.
There are ALSO the rifles which came from the HMS CALYPSO/HMS BRITON while she was busy being the entire Newfoundland Navy. These were primarily Lee-Metford Mark II rifles, many of them commercial rifles marked LEE-SPEED. There were only a couple of hundred of these rifles and most of them were shot to death because (1) they had to train an entire Army (although a small one), (2) the ammunition in use was Cordite Mark II and VI, both loaded with highly-erosive Cordite Mark I, (3) the barrels were Metford-rifled and Metford rifling did not tolerate high flame temperatures very well. They MAY also have had some (Long) Lee-Enfield Mark I or I* rifles, but I have not seen any. Check out the old photos which hang in most Legions. These rifles will NOT have the NFLD Butt Marking Discs because (1) Newfoundland had NO armed forces at all before the outbreak of the Great War, and (2) the LM Mark II marked on the Butt Tang. Being that they were, officially, NAVY rifles, you MIGHT find one with the Naval N on the left side of the Body, but my rifle is genuine and it is unmarked.
Hope this helps.