I believe in some states you can lock longarms in a wooden cupboard - provided it's not easily penetrable and has a lock of sturdy construction, but as already mentioned - I don't think this would pass.
Another problem you might face is that if it weighs less than 150kgs, it needs to be bolted to the premises, which IIRC most friges are off the floor with stoppers.
Interesting concept, but I would imagine that a fridge would be easy to penetrate even with a lock on it, so would not be accepted.
Plus -
more importantly the guns are taking up space that cold beer could be - so it's definitely not acceptable in Australia - regardless of the state one lives. (Well, maybe with exception to Queensland coz they wouldn't know real beer if it hit them on the head)
