I have a Crook Custom that has a FATHEAD brass contoured plated mounted to the rear of the headstock. I purchased this guitar second hand and it is about 10 years old. The person that I purchased it from said that he had taken the guitar to Bill Crook not that long ago, so I called Bill and he said he had seen the guitar. I asked him about the FATHEAD and he said that he used them on many of his guitars back then and really liked what they did for the sound. Basically it adds mass. He said they were no longer made and wished they were still in production. I have never seen one of these before and have not come across any on eBay. Does anyone else have one of these? Just interested.