Blow by and oil dilution of the air fuel mix, and things like timing chain wear which are common to our small sixes will alter your warming up tune, and you'll see that on your air fuel gauge if you do 5 minute verses 15 minute light off air fuel tests over the same territory. Nothing you can do to the jets, air correctors and e tubes will help much with that.
Bill and I like to do a cold cranking compression test, and an 8 hour or 24 hour static leak down test to baseline the internals are ok.
Then check that the vacuum advance is stable and the static advance is not hanging up, and is suited to the engine tune. Even re-routing the vacuum line can make massive change in how you set up the curb idle and lean cruise and transitions.
Once you got uniform, repeatable advance figures, and you know the cylinders are holding an 80% leak down, and as long as the cold cranking comps between cylinders are stable within +/- 15% (that covers your lifter preload or clearance, cam condition), then you can have fun base-lining your tune safely without going on a wild goose hunt.
The basic work you've done is fine. Plug reading teed into your wide band will tell you more about engine condition.
Enjoy getting to know how your engine ticks. I'm not a wide band guy, I like the basics, because a wide band is a seriously sharp piece of kit that needs a lot of brain in the head verses Seat of the Pants "Rectal Checks". Going to a wide band normally takes your
1. tingling palms,
2. 4500-5200 Hz hearing where the start of audible knock happens, and
3. butt-o-meter off the feeling of lean miss-fire and transitional responses. These happen in moderate grades, where and engine labors, and you can tune for elapsed times between station points.
Your five senses need to be tuned into how the combustion process works, and Color Tune, Narrow Band, and Plug readings at wide open throttle on cut ignition teach you a lot more than a Wide Band used first.
You have to spend much more time, and a wide band forces you to work at depth. I worry about safety in that enviroment, but a cell phone is no different.
The 6th sense for tuning is putting all the the things together. A wide band won't hurt ultimately, but your suddenly a NASA technician now Ryan.
Old car tuners were forced to take a step back. A wide band forces you to analyse the charts, and that takes your eyes off a vibrating hood, a harmonic tap that your ass or feet feel, or the kangaroo hop and pig rooting an engine exhibits. When my teacher, hot off the Ford Service Technican courses, had me setting up engines, it was always exhaust gas Co's, and then a quick test run, and revise. He'd tell me about what a lean missfire is, and how you checked your mean best torque ignition setting.
I'm not against a Wide Band. It just forces you to stop flying the engine tune by the seat of your pants. I'm sure Bob Wallace (Kiwi guy who de-tuned the 400 hp at 9000 rpm LP350 engine to a 320 at 7500 rpm road car engine at Lamborghini), I'll be he used a Wide Band, but I'll bet when he sanitized a V12 engine tune, he used all his senses, and worked from Ignition, Plugs, and then Weber tune basic, then when he had it in ballpark, a quick O2 sensor up the exhaust on a rolling road. Or a 170 mph smash over the Alps to France....
Anyway, Your in the Big Time, and listen to Bill and others that have had a go with a Wide Band. Its a wild ride!