After spotting a thread on Lead Adventure Forum (LAF) this morning bewailing the discontinuation of GW's washes (particularly Devlan Mud, a spectacularly useful addition to my own painting 'skills'), a really helpful link was posted by Major_Gilbear pointing to this blog entry at From the Warp. Suffice to say that I'm already planning an order of the mentioned Army Painter inks.
The summary of the post is:
Army Painter Warpaints Dark tone ink = Badab black
Army Painter Warpaints Strong tone ink = Devlan mud
Army Painter Warpaints Soft tone ink = Gryphone Sepia
Note that it's not the big tins of Quickshade that is being talked about here, but the inks in their Warpaints range.
Hope that's as useful to any readers as it was to me,