For scuplted woodgrain, I find that painting + inks gives a nice effect for little time/effort expended. I use RP Leather and wash with brown ink and thats it (except for some dullcoat after to get rid of that ink shinyness). I\'m not sure what the closest equivalent would from GW, probably bubonic brown or snakebite leather. I think Vomit brown and Leprous brown are too orange, but they might work also, the ink would dull our the orange a bit. Anyways, hope this helps!
--Katie G.