Thanks for the tips, both of you :) But that wasn't the problem.
It is now fixed. I removed the level plugs and turned the electric pump on. I promptly discovered that the secondary level was too high - but the primary was pouring out of the hole and I know that's not where I set it.
Removed and cleaned both needle/seats. There were a couple of tiny shards of what I think is an old level nut gasket... anyway I reinstalled with three threads showing, and carefully backed the nut counterclockwise on each until I could just get fuel dribbling out the hole. Then I turned them back 1 flat because the engine was cold. Warmed it up and went for a drive - back to normal, idling in the high 13's as usual. No more AFR "creep" or flooding!
:thumbsup: