Decided to check if the switch contact was "making", and even though I had cleaned the momentary contact previously, it was not showing continuity through the switch. Took the switch assembly apart again, and decided the issue must be the Pivot contact in the switch. This is a contact Bar situation, where the bar makes contact with 2 points to make the circuit. The bar sort of rotates about the 1 contact and touches the 2nd momentary contact. That 2nd contact was fairly easy to clean, and I had done that. Never though about the other end of the bar, that is in constant contact with the 1st point. I was able to retract the spring loaded bar enough to get a blade into the 1st contact area, and scrape it clean. Switch together, signals cancel. So it WAS the switch all the time. Related this process if it helps anyone else with a no cancel problem.