Update: I gotta get a new O2 sensor and then sched up a time on the dyno. Had some issues with idle and it finally threw a light. Gotta get some more $$ so that I can do all this. BTW, I think that I will make a decorative piece out of the cam. Might be a lamp, but who knows.
I inspected the Capn’s camshaft failure parts and discovered the offending exhaust rocker’s roller pin was offset. Either the rocker casting or the roller pin race was cross-drilled incorrectly. Under magnification the pin could be seen separated from the stakes on one side. At valve full lift rocker angle, the pin would be cocked to one side causing the roller to drag across the cam lobe surface, this friction combined with valve spring pressure created mechanical spalling. This is akin to tire wear from excessive toe out. I’m told rocker rollers are much harder than camshaft material and this is probably why it cut so cleanly into the lobe at its edges. Measuring the rocker bore with a bore gauge revealed it was ovalized for whatever that's worth.
As it turns out, all of the exhaust and a few of the intakes on a recently installed new rocker set were defective. The photo below shows relatively minor pitting on the roller compared to the others. If not for a PTFE coating on the cam lobes, damage would have been worse. It appears rocker defects are more common than I realized. There was also one rocker with a blob of casting slag in its bore causing it to be a tight fit, and probably contributed to extra noise.