Well Barrowmaze is an exellent megadungeon as far as I can tell. However, I need to make some minor changes to make it fit in to the Barbaric Frontier campaign. Most of them are pretty cosmetic like changing names to some german sounding. Others are more invasive like replacing mongrelmen with beastmen, and subhumans.
Here's list that summarizes all my changes:
mongrelmen - beastmen, subhumans
Nergal - Hydra
Orcus - Uglu(Deep One)
Set - Muruu(Deep One)
the Acolytes of Orcus - the Acolytes od Uglu
the Necromancers of Set - the Mystic Cabal
Location of the Barrowmaze
One day of march northwards from Neuburg into the Blighted Moors.