I've been looking into getting various bits to help step up my conversion game and I've had a lot of success finding various bitz and bobs at 54 mm (hands, feet, heads, etc).
The two details pieces that I've found elusive are boots and bare skulls. Anyone have a good source of these bitz? Historex is where I've gone for most of the other stuff but I didn't know if there's another good source so I thought I'd throw it out there.
The skull I use is the plastic one from the warhammer fantasy command sprue. You might could find someone selling the bits online. I also have skull piles made by Lemax in their spookytown halloween decorations, they are very 54mm.
The original GW 54mm skull form the Imperial Model Booster is still available on their site along with various books:
http://www.games-workshop.com/gws/catalog/productDetail.jsp?catId=cat440122a&prodId=prod1290127
My =][= scale Kroot Mercenary came with a metal 54mm human skull, not sure if it was supposed to be part of the conversion pack or whatnot.
I got some 54mm skulls from battle forge miniatures of ebay. The seller doesnt seem to have any right now, but they arent bad casts. Seller was From_Fire_and_Flame
Love the link to that scenary pack - an inquisitor of mine is an obsessive book collector ... I feel a new model coming on, damn you for inspiring me!