I have considered doing this exact project, but someone beat me to it (while I was delaying and worrying about not having much experience carving wood)! Guess I'll have to learn to be more willing to ruin some wood making mistakes and maybe start out with a different sigil for the sake of originality when I try it...
Cast aluminum Targaryen sigil plaque:
Came out looking pretty good IMO... Perhaps the carving could have been a little more detailed so the relief details would show up more in the casting, but at least he actually made something. That goes a long way in my book.