Wipe each key clean with a dry cloth. Dip a corner of the wax cloth into the dark wax and work it into the surface of the key, getting into any engraved detail or joints. A little goes a long way: use less than you think you need. Leave for two minutes, then buff with the clean cloth using brisk, circular strokes until the key has a low, even sheen. The metal should look darkened but not lacquered.

Cut a 60 cm length of ribbon per key. Thread one end through the bow of the key and fold it in half, aligning the ends, so the key hangs at the midpoint. Tie the two ribbon ends together in a simple knot about 5 cm from the top, leaving a loop for hanging. Repeat for each key.

Lay the shadow box flat and arrange the keys inside it before fixing anything: vary the heights and angles until the grouping looks balanced. When you are happy with the arrangement, press a small nail or picture pin through the back of the box at the hanging loop of each key, bending the pin slightly to hold the ribbon in place. Close the back of the shadow box and hang it level.