Considering the massive market for alternate Orks and Ork bits to add to GW models, I'm surprised no-one has gone for a pith helmet option. Maybe WWII German Orks are more popular.
Taking advantage of the next best thing, being Curious Constructs pith helmet Ogres, I have started on a Blood Axe mob who were obviously impressed by the way the Praetorians died at Big Toof River!
Taking clippers and files to the helmets, I've hollowed out enough for them to fit on Ork heads. I just need to order some more from the Kirton Games store as I only have seven at present. Additionally, I need to wait for a week to check out the full Kill Team rules. This Mob may be upgraded to Kommando status.