Ignition wirng harness

Car is 71 duster 225 points. New points, condensor, starter relay. On going project, it had sat for quite a few years before I got it, got it running, tuned. Not yet insured so it only gets a 1/2 mile check out trip down the road. It does this occasionally. It is started and warmed up, I might move it and engines dies. I try to start and then nothing at the ign switch. I can wiggle the under column connection for the ign swith harness and it will start. OK . But soon as I try to check the bad wire)s) there, with test light probe, it wiggles enough and makes connection so that tells me nothing.
Since I ( and credit card) just spent $1500 at the dentist, I really do not want to order a new harness. My question is 1. Since it will just die I feel it is losing a connection somewhere to cause this. and 2. I want to jumper/ splice whatever the bad wire (s) are at that under column connection for the ign. harness: Is the culprit, the yellow wire to starter relay? The Hot wire there, OR the blue or brown ign, start/run wires??? I have cleaned this connector with a brass wire brush, applied some dielectric grease. I have run my large HOT (Red and Black) wires directly thru the bulkhead. I have cleaned the terminals at the amp gauge and do not want to bypass it.
I figure the part of bad under column connection is likely the end that is the ign. switch harness part. I don't want to lose the dash side of the connector, as I would probably order a new ign switch harness sometime in future. Would a jumper wire spiced in be reasonable cure for now, BUT which is my bad wire at the connector?????
Thanks