Another successful application of the venerable WO!
Nice going, Bassman.
I know you can't just leave those Carvins sitting in the wings, so how about building another cabinet for them (similar size front) and leave it sealed for the hi-end response. Bi-amping would be better for this idea, but it might work fine running both full range if you get the phasing right.
Just be sure the impedance is OK for your amp when you wire it up.
You definitely don't want to mix mis-matched drivers in this cab, but you could always build another WO and put it on the other side of the stage. Tell the guitar player you want one for your ankles, too.