Got it in the ballpark with the wideband. But you can get wrapped up in your shorts with too much data, so I took it off when I got close. Drove the car for awhile, cut some of the plugs with a hacksaw for a good read, and the only change since then is leaning out all four jets by one number. Car runs and idles well, and the plugs are clean.
Run on is a different matter. Since my car needs to idle at 1200 to
oil the solid rollers, it's prone to run on simply because of the idle speed. I think Chas suggested I put the car in second, put the parking and regular brake on, and let out the clutch slowly to drag down the idle speed. At that point I cut the ignition and let the clutch out fully. Sounds scary but it isn't. Very easy and solves the problem with a racy engine.