> Although I suspect that's probably cockpit side of the door!
Your suspicion is 50% correct. One is in the cockpit, the other is in the rear galley. Depending on plane type, but this general rule applies to the most common airliners.
And no, I don't mind you knowing where they are (which besides, anyone with an internet connection can find out in a few clicks). The level of aggression required to cause significant damage with that is not something that sane, untrained people posses. As for those who are trained or insane, they don't need a fire axe in the first place... they can do just as much damage with the tea kettle and food trolley, amongst other things.