I dont know which one it is, but it doesnt make that much of a difference does it?.. I mean just buy the one that is in stores now.
Anyways, i tried with leather brown, i think, and it had a very bad effect! In general the colour primers are hated here in Denmark for their bad effects.
They made my skaven unit's skin all crunchy and are impossible to paint. Many have had the same experience with the colour range..