i picked up a old whites Gold Master--Mineal & Metal Detector it has a blue box with a meter on the front top 0--5--10--15 DC Volts, a battery check switch Off 9--12, a volume switch, ON/OFF switch, and a round MINREAL O METAL tuning knob,,it has a black plastic search coil with a res sticker on the top it says gold master and has th #s S63TR on the sticker, is there any known history or info--price quality anything on this MD thanks BOB B