Car died during driving

Good day. I have a 1972 Demon. Problem that happened last night while driving my car it shut off while coasting to a stop. Tried to restart.. Nothing happened. No lights or anything. My ez efi is on a separate switch. It came on but nothing from the key. After doing some wriggling of wires associated to the starting system and ignition switch connector it started up. Drove to the store... Come out to start nothing.... Did the same thing I did first time it started up.... Drove for some food. Got in the car started right up. Just come in from checking connectors and such...All are visually good minus a VERY slight Browning of the ignition switch connector where the solid red wire is. My neighbor who is WAY better than me at electrical problems suggested my battery is acting up.... It's an Optima red top about 10 yrs old. Sat maybe 3-5 solid years of that time. I was thinkin along the lines of ignition switch. What do you all think? Sorry so long tried to get as much info in...lol