Might be time to start looking at the FSM for your year.
With all that you have changed out, there's a chance that something you reinstalled is either not wired correctly or not the right part for your vehicle.
That low voltage reading on your coil (+) (5v) seems suspect to me.
Is it possible you have the wrong coil, ie. one with an internal resistor? Or, you have some other IR drop between the ignition switch and the coil (+)?
To check that 12v line feeding your ballast resistor, with your battery terminals disconnected, check how many ohms you have between your battery positive terminal and your ballast resistor with the ignition switch in the ON position. It should be near zero.
If that checks out OK, that means you have too much current drawn downstream of that point.
I'm not a points guy, but I believe there should be no current draw through your ballast resistor or your coil when your points are open, and therefore you should have a full battery voltage at your coil (+) with your points open and ignition ON. Is that right?
If you want to start going through the FSM to verify the components in your ignition system, it's a great resource and a great way to learn. You can find the free download link here somewhere.