I know, sounds goofy, defiantly not fireproof! Was looking at my huge scrap pile of 3/4' plywood and other assorted lumber and the thought struck me. With enough layers and lots of screws & construction adhesive holding the layers together it could be better than a cheap safe. If the inside were lined with those adjustable metal shelf strips, and with all the screws and double 3/4" plywood, a saw would be sloooow going. I know because part of my wood scrap pile came from a MASSIVE homemade overbuilt entertainment center I inherited when I bought the house. It took me near a full day to cut up/dismantle! Being wood I could customize the dimensions and maybe disguise it as part of a wall divider as well.