["QUICK-SILVER"]

Unhook the condenser at the coil. It's a radio capacitor and will run without it. For radio static only, has nothing to do with ignition spark. It's suppose to be hooked to coil (+).
Having it hooked to coil (-) is like having two condensers hooked to the points and could definitely make the coil spark weak. Especially in run position where power is resisted.

Curious about your 6 volt reading and how you hooked the tach light to only burn while running.

This one should be as easy as it gets.
Knock on wood

Get the gap/dwell checked on those points.