I'm a member of the NRA, the NFA and the CSSA, and I can tell you right now, you're not going to get support from any of them them. We've solicited the NRA for help in Canada for real firearms and while we have their moral support, they don't see a mandate to push their agenda in another country that only has a handful of paying members in it like myself. Are you a paid member of any of those organizations? Why should they defend your property rights regarding replica/imitation firearms?
You can try the NFA (Canadian version) but they are doing all they can just to hang on to Canadian firearms owners rights, they're probably not going to spend much time or resources defending replica firearms, and some circles in the firearms community would agree about banning airsoft guns - so I don't think thats a productive direction either.
Ultimately the response will have to come from this community. There are members here that have been engaged in a dialog with the government on and off for some time. So like I said, I am waiting for more information (24-72 hour timeframe) before I say or do anything definitive.