There was a gentleman in New Orleans, when I was last there, who did some rather unusual repair jobs on some of my friend's guitars. The fellow was from one of the Germanic countries and still had a heavy accent from his country of origin and an "old country" name to boot. As a repairman for instruments he was quite good and came well recommended. He had this kind of spooky shop, that was dimly lit, with violins hulks hanging from the rafters everywhere and it made me wonder just what kind of voodoo this guy performed when he wasn't fixin' instruments. My friend showed me the job that the guy had done to his guitar. Inside the soundhole was a strange kind of homemade contraption mounted to the back. It consisted of a balanced kind of teeter taughter gizmo made of metal that was meant to increase the volume or resonance but I'm not certain if it actually accomplished anything at all except to look very odd. I had the guy fix up an old violin that I had bought at an auction while I was there. He did a wonderful job of getting it in playable shape, but I don't think I would've trusted his repairs on my guitar. He was experimenting with some very other-worldly radical ideas.