Any suggesttions what to overspray an electric guitar with, that has a bunch of autographs on it? It's a Yamaha, so I'm sure it's some type of polyesther finish on the guitar. The signature are in some type of silver marker. A customer thinks this low end guitar is suddenly valuable because some morons wrote their names on it, all writing is totally un-intelligible. Thanks. I'm trying talk them out of this.