figuring out advance timing

The stuff I linked to should help. Except maybe Shrinker on how a wideband gets fooled. That might take several readings and a few days. LOL. But that's not neccessary to set up the timing table.
If you're asking for my comments on the table you just posted-
Experiment with one thing at a time.
Look at the spark plugs now to see what they show under the current conditions.
Adding timing to the baseline (atmospheric) is the most likely to cause damage to the engine.
I wouldn't touch that or anything near that until you have an opportunity to put the car back on a chassis dyno or maybe the 1/4 mile if you are careful and are able to back off the throttle during a run.
See the example in post #10.
Many Chrysler high performance v-8s needed enrichment when vacuum dropped below 8.5"Hg
Some of the GM high performance engines needed to be rich below 10.5 "hg.
Assuming your hot rod is going to have similar or worse part throttle fuel distribution and combustion characteristics is the safe bet. In which case, leaner mixtures and additional lead time should only be added when vacuum is higher than 8.5 to 10.5"Hg.
Hopefully that clarifies why I boxed out the area around 10 to 11 "Hg for the beginning of vacuum advance.