I've seen it on Original 1970 cars,and up to 1971 vehicles in junkyards.I wouldn't say for sure it was original to all of them,but then it could've worn off too.(How they heck can it even wear away out of that recession anyway?)
I've had a few of those ignition switches NOS in the box,and they have the Flat Red paint mark too.I do see it visible in some of the 1970-71 35mm Chevrolet Dealer Filmstrips.
Possibly more then one plant made the switch for GM,and therefore the indifference?
I do like to see either a properly restored car,or survivor having this red mark as well as the Key Minder Buzzer working too.
Floats my Boat!
