[n86121]

I think I have them all traced correctly now.
Believe it or not, many transition to firesleeved hoses so it is a bit confusing!
Retracing a bowl of red spaghetti backwards from each end.

When mixture in detent. Cleanly shuts idle.
Is definitely in full idle against the stop.

Doesn't drip immediately on shut down, takes a while before ...drip drip drip.

Drip from LR cylinders definitely stops w fuel closed overhead.

Still drops with newly overhauled flow divider from QAA.COM.
Still drips after a while, and then endlessly.
Flow divider spec only supposed to hold 1 PSI for 2 mins.

Thinking what else could be seeping fuel into cylinders, ...I thought of hand primers...?

Noted from your comments,
I discovered (after 25 years) that hand primers have a lock position.
I have used them so rarely, I never noted the actual detent position before.
Generally I'd just push them in and twist, but apparently not locked.

Fuel back on.
We will see if drip resumes with primer in detent.