U.S. and Canadian laws regarding deactivated weapons are substantially different. As Chris mentioned, in the U.S., the receiver is basically what constitutes a live vs "dewat"... in Canada the laws are quite strict and much different.
I'm sure others could advise you much better than I, but suffice to say that your Canadian dewat must have its barrel welded and pinned, the bolt faced milled out, and it cannot cock & click, nor be field-stripped. But there's also a gray area here, for technically, "replica" guns are also illegal, and anything Sten-like you build could technically be construed as a "replica". They'll charge you FIRST, and leave the onus of proof of innocence on YOU.
I cannot advise you re reenacting, but for display purposes, buy a legal dewat here in Canada; but even then, treat it like a firearm in terms of handling and storage, else it come back to bite you in the bum. I cannot emphasize enough that dewats are currently held at the pleasure of the government only, and that the first time there is any incident which reaches the media, the chances are good that privilege will be revoked.
Better you stick with a tried-and-true No.4 Rifle and be done with it. There's a certain honour in being a Rifleman, y'know...