OK, I've just been double checking for ya. Al's 8 string copedant (as used with Burritos) is detailed here:
Al Perkins 8 string copendentI can't find his ZB copedent online but I know how he has it set up. The tuning is an E9 chromatic but he has a low E on the bottom end. It goes like this (low to high) E B D E F# G# B E G# Eb F#. He has a combination of the normal pedals and levers and also some more unusual ones. Pedals 1, 2 and 3 are standard. He has the standard E-Eb and E-F levers. Add in some more non-standard ones like low E-D, B-Bb, Eb-D/C# and high F#-G.
You can play most Al Perkins stuff on a standard E9 setup, but you'll miss those low slide ups he can do with his low E string.
Here's a tasty clip with his Fender:
video: [
youtu.be]