I tried to adjust my guitar in many ways today, and ended up in breaking the small white plastic part, the tightener or washer or whatchamacallit in english, that sits on top of the tuning heads, right below the screw it self. This happened when tighening the screw on top of the tuning head, for better response when tuning. Now, where can I find a single tuning head in gold for my Dave Navarro SE? Only sets of 6 at eBay.