Great tutorial! I like the idea of using plaster to fill in the gaps between the pieces of cork. The only thing I thought of while watching the video and seeing the end result - what if you made slight indentations into the plaster in the cracks, so that it was sunk down more below the cork - thus the crevices would be able to have more oil wash pool into them, adding a bit more dimensionality. I will have to give this a go myself!
Thanks