[RichardJ]

>> I read just over 6 volts at the coil with ignition on,<<

The engine just happened to stop with the points "closed". The next time you turn the engine off, it may stop with the points open. You will then read battery voltage on the "+" and "-" post on the coil.

>>engine running read 12 volts at the coil,<<

A DC volt meter is used to measure a DC Voltage. A constant DC voltage.

The ignition points is a switch. A V8 ignition fires 4 plugs per engine revolution.

At idle, the DC meter is trying to measure the voltage on a switch circuit that is opening and closing 4 X 650 = 2600 times a minute.

That "resistance do not cut" wire doesn't look factory to me, but what do I know. It should measure about 1.6 Ohms end-to-end.

>>A set of points would probably last me a long time, this truck won't be a daily driver,<<

Points will generally last 10k - 15k miles, depending. Sitting unused, corrosion will shorten the life somewhat.