HI GUYS I HAVE BASS COULD BE A EARLY YAMAHA 70S 80S/ IT HAS A VOL POT/ THEN THERE WAS A SWITCH/ LEFT ON /MIDDLE OFF/ RIGHT ON/ THIS WAS BY PAST AS BROKEN/ THEN THERE IS ANOTHER POT SEEMS TO MIX PICKUPS/ THEN A TONE POT/ THE POTS ARE MINI/ I WAN'T TO UP GRADE POTS ETC/ BUT DON'T KNOW WHAT THE...