Love it. Definatly bang some clear on that. Would make a great display piece. As for the tears, I attached a sketch that we did for a job we are working on, for the client to get the idea of what 3-D tears/rips are going to look like. It's not painted yet, but you can get the idea. Just try to get some depth and uneveness in the tears. Also, notice how on the edges of the jagged pieces of metal, that they dont end smooth, but they overlap a bit from the tears. Kind of a rollback effect. That also allows you to do shadows on the surface (your skull) and on the metal that the skull is coming out of and a second shadow on the metal from the overlap.
Look forward to seeing where you end up on this.
TABG
Airpower Art Studio