Ork warlord in Ooba Armour

This is my work-in-progress warboss, Gorbag Bogroll, in Ooba armour. :-D

I used parts from 2 defiler kits (the spare parts of which were donated to various other orky treats) and a ghazghull torso. Originally he had a ghazghull head, but I swapped it for the assualt on black reach warboss head to give him a bit more character.
So far he's armed with a twin-linked big shoota, a twin-linked skorcha, and a kustom-mega-blasta.
Not sure what to put on the top, as at the moment there's just a whoe there. Eventually he'll have a banner or two, and a couple more weapons.

I'll use the vehicle design rules to calculate the rules at some point, making it a walker transporting 1 ork. Though it has been suggested that I count this as a battlewagon transport for a warboss, which would work just as well for simplicity's sake.