Hi, I just acquired a PRS SE Santana 2012 model. I'm trying to determine whether or not I should replace the nut. It looks like it is made of plastic. I asked a rep at PRS what the material was and he told me "synthetic material" - sounds like plastic to me. But, before I replace it, could it be made of their proprietary self-lubricating material, or do the SEs simply come with plastic nuts? Thanks!