Not that I recommend this, but it was just a passing thought.
A guitar case with outter locks, thats inside has been modded with a foam insert to hold the AEG. Atleast you wouldnt look like you were transporting any firearm. However I do understand at the sametime the issues that could arise if a person were caught with something like that. Realistically a locked gun case is your best choice, however I am not farmiliar with your local transit laws, so I will not recommend anything.
"Its only a little bit on fire"