I have an old garage paint and flammable stuff locker 72 X 20 X 36, that I got for free.It's about the same gauge as a stack-on locker but welded. I modified the locking mechanism with a stronger round key lock and 2 inch flat bars instead of the 1/4 inch rods that locks up and down. I also made holes all the way through the doors to slide another 2 inch flat bar horizontally and locked that with a hard to pick padlock (nothing is pick proof). Even with tools someone would have a hard time getting in, and we all know a burglar wants to go out in a hurry (5 minute max) That would suppose that same burglar would know what's in it because it doesn't look like a "safe" or that it has anything important in it. That is also a good point to consider, make it look like it's a normal piece in the room.