Had I imagined the switch contact to be at fault I wouldn't have known to repeatedly engage the grip switch; to wear through the oxidation film. Silver doesn't corrode, but oxidizes. Who'd have known what 46 years of sitting, unused, would result in such a malady. A Professional found it out. Sambo said it wasn't a quick and easy job.
Still working on attending to loose 5 pin mic to radio connector. Original Cobra Coffin mic works perfect. New connector installed onto Golden Eagle mic cord, female, connections not so great. Simply could be brand (manufacture) of connector.
Diameter of round/female contact points not making solid connections. Reshaping required. Thus far Rugby football shaped contacts has greatly improved connections but not 100%, still flaky. Tightening down on securing ring may cause loss of connection; no audio or modulation. Will reshape to American football for greater tightness.