....I had thought that maybe it was a common problem and forum members would have known right away where the oil was coming from, but evidently I must have overestimated the commonality of the problem/symptoms.
Which part of the word guaranteed don't you understand? The evidence of the source is in your own pictures (as has already been spelled out).
I've been down that path. Traveled this road. Crossed that bridge. Run this race. F#cked this cat.
OEM LA valve covers buckle, get bent, are distorted over time. No-one torques them correctly. They go too far, then tighten them a little more. If a leak occurs, they get tightened again!!
You have form for ignoring advice and whoring up forums with thread after thread. I'm done here.