Hi I just got this P bass probably about 1983 Nice bass. I have a few questions about it. First the controls... Who would help me with the rear toggle switch as to what it does? Secondly it is missing the four screws for the fine tuning does anyone know where I might get those? Perhaps ones off a Musicman or G&L would fit? And it is missing one of the three black rubber covered knobs. I need to try to find one of those. Any suggestions or chance of finding these parts? Thanks.