Plug readers: What would you do??

It’s very hard to tell because the plug is so contaminated, and overly rich, but the ground strap in your 2nd pic (cleaned off plug) almost looks like the timing mark is wrapped all the way around the strap to the base thread. And judging from the look of the electrode and strap corners you have too much timing in this engine. If it were mine, I would (in this order)
1. Pull 2 degrees of total
2. New plugs, 2 heat ranges colder
3. Add octane, maybe 116
4. Pull fuel from the map
Test and see what the new plugs look like.