Your gun, and I suspect being Canadian that you know this, was shipped to the Mounted Police. It may well be one of the LAST New Services that they got. Looks like it was "never issued", or spent its police career in the desk drawer of an administrator!!
This IS the FINEST example of an ex-M.P. New Service, that I have yet seen, and living in Maine, I've encountered "a few"!
The "mounties" began using the New Service in 1904, roughly 5 years after Colt introduced it(it replaced the Mounties "hermaphrodite" .476 Enfield revolvers). Earliest New Services were shipped to Canada in .455 Eley caliber, and marked NWMP. Later batches of guns were stamped RNWMP, and .45 Colt replaced the .455 as the chambering(.455's were used WEST of Winnipeg, .45 Colts EAST of there to simplify "logistics-although with the old and superb Dominion brand ".455 Colt" ammo, the .455's were plenty powerful.
The New Service was standard issue until 1954, when 5" Smith & Wesson M & P's, in 5" bbl. and .38 Special were issued. A step BACKWARDS, in my opinion [img]/forums/images/graemlins/frown.gif[/img]. The New Services and their "leather" were then sold as "surplus".
Identical configured guns, to yours, were also shipped to the Canadian Navy, in Nova Scotia, I think, around 1941.
The number on the backstrap was the inventory number for the Mounties, beginning with #1 in 1904.
Glad to see that some "gun trading" can still happen in Canada. Will occasionally meet a Canadian "tourist" here in S. Maine, and they lament about the very strict gun laws, especially for handguns up there. I can recall in the late 50's-early 60's,that it was relatively easy to legally buy/bring even handguns across the border, at least in the Calais(Maine)-St. Stephen(NB) crossings.
Get a copy of the small paperback, "Small Arms of the Mounted Police" by Phillips and Kieby for more info.
Hope this helps some.