I am lucky enough to have picked up a 69 Deluxe Reverb the other week. It's got this roque black wire off the footswitch where it plugs into the chassis. It looks like there is a little nubbin it used to attach to at the reverb RCA input. My instinct is to strip the black wire and solder it to the nubbin. Can anybody offer informed guidance on this? Detailed explanations of the finer points of the fix are welcomed and appreciated.