Artillery shell casings. Started with a USN 5"54 that got made into an ash tray during our Westpac cruise. Found a few in a local scrap yard, two were from an uncle who served with the British army in WWI some found in antique shops and some I bought off ebay. Knock out the dents with a soft blow hammer, sand down to get the scratches out and then a few hours with a home made polishing rig I made out of an old table saw motor which is is as old as me (71. And pocket knives, seems I cannot resist picking up another one. Benchmade, Buck, Spyderco, and others. Frank