small antique tinned box, traveler's deed box, instrument case, tinder box?

We love this tiny metal box with it's hinged lid and lock-ready hasp, though we have no idea what it was originally intended to contain! It's heavy steel, with a worn tinned or galvanized finish inside and out. An instrument case? a very small document box? a box for matches and / or tinder? Size is 4 1/4" x 2 1/2" x 3 1/4" tall.