How about a clear lower receiver? That is what makes Canadian legal lowers not replicas correct? It would be costly to make a mold then to get injection equipment so that isn't gonna save any money I guess.
Also what about a lower receiver that is not really in the form of a normal AR-15 Receiver? I actually had a design request to design upper and lower AR-15 receivers that looked radically different. Kinda the thing that the authorities would get up in arms about but I'm guessing you could make a lower receiver that could function with the rest of an airsoft gun that would not work with a firearm and still look different enough as to not appear a firearm.
It just seems a lot of the dos and don't are rather convoluted and I was hoping for some fair opinions from some experienced people instead of just being told it would cost more and that I am stupid cause I'm new to airsoft guns and have yet to pull 10 or 20 apart and memorize every internal and external part.