So I found a technical manual document with the conversion tables for enterprise and unified scoring. I've used the Enterprise scoring for these:

Reading = GE 10.3, 90th %ile, NCE 77.0
Math = GE 12.0, 92nd %ile (first month of grade 6), NCE 79.6

There's some other stuff on this page too, for predicting ACT/SAT on-track progress, but also three little links to the technical manuals, which is where I found the conversion tables.

...pronounced like the long vowel and first letter of the alphabet...