Your welcome.
Seriously, if your in the room at night just keep it the way you have it and lock the bedroom door, no toddler is going to get past that, use a key lock if your paranoid. Plus that way the kid won't walk in at an inconvenient time for you and your wife. You could even lock the door during the day when your not in the room if you do go the key lock route.
As soon as your kid is old enough to understand teach them gun safety, and let them look and play when they want, provided you are there to supervise. If you demystify the gun, make it it just a normal "meh" object around the house the kid will have no interest or reason to try to sneak around and find some way to play with the forbidden toy, because it is not forbidden, so need to try to come up with eke erase storage solutions, a locked door will do just fine. And by teaching gun safety, if they DO manage to get unauthorized access, or get access to someone else's, they will know the proper, safe, way of handling it. This is the best method.