Great start on derailing a thread...
I'm guessing OP's talking about using parts kits to build a non-functional MG42 to put on display. It probably wouldn't be a replica because it would use MG42 parts, rather than parts that were never intended for actual use or capable of such use.
To OP, you can usually find parts (they're expensive) or may be able to get a parts kit imported. I don't think the RCMP would object to a non-functional MG, especially if not built to spec and incapable of being so (IE aluminium receiver or no internal fitting).