Vintage Metal Case best decorated with Hardware

Here's a one of a kind old hinged metal case (with plastic carrying handle) decorated with recycled hardware bits, keys, clock gears and indicator lights, etc.
All the decoration items are used and vintage - there are inherently scratches and dings, etc. but the photos are true to how this looks! (approximately 15" x 7" x 2") Please look closely at the photos, the base of the box is good condition but not perfect, and some slight rust, but it is best sturdy and has great character!
A really fun piece!! What will you keep inside this special box? :)