Only drop-in parts that will convert an unrestricted or restricted firearm to fully automatic are prohibited. Full auto fire control parts for the M14, M16, or any other firearm that will not function in an otherwise legal firearm are still legal. These kits are clearly kosher according to the law. Unfortunately, Canadian Customs does not directly refer to the law, but to an interpretation made by their agency for them. If you want to know for sure, phone and ask them. Make sure you emphasize that they are cosmetic and non-functional.