47 V8 ignition mystery

[Old Henry]

I just rechecked the impedance of my coil.
Primary was .7 ohms. Close enough to the prescribed .75 to .81 ohms.
But the secondary coil impedance was only 5,500 ohms, half of the prescribed 10,000 to 11,000 ohms. I don't know if that's off enough to cause my problem but I just ordered a new coil hoping it fixes it.

I'm still very bewildered about the poor, if any, spark to my #6 cylinder.
I have good continuity from the distributor cap to the sparkplug end of the wire so the problem isn't the cap contact or the wire.
Can't think of what else it would be.

I do have some brass shavings/particles inside the cap. I'm thinking the rotor has hit some contacts and wore something away. I don't see any obvious wear to any contacts. I'll blow out the particles and maybe shave the rotor down slightly to keep it from hitting and hope it improves #6 spark.