Maf translator question

[BLACKRONIN22]

I have an old style maf translator with the old white adjustment knobs and the markings for which adjustment are worn off because it is pretty scratched up. So my question is how can I tell what setting they are at? Any help would appreciated. Oh yeah I have a check engine light for rich idle and I was recently adjusting the translator thinking I knew it what setting I was on but apparently that was not the case.