Just a note, make of it what you want and I don't need or want an answer, this is merely for you to think about. If you ever have to use it for self or home defense if it goes to court a skull motif could be used against you. Anything like that is best not put on a gun for SD. If it's purely a range gun I don't think there's any harm in it. But modifying a firearm to make it yours? Go for it. Everyone does that to one extent or another. If the potential for SD is there then you must think about the message it sends to the investigating officers and the prosecutor. In some places if a firearm is used you're already "guilty" to some prosecutors trying to make a name for themselves. If the media gets their hands on the story you'll be tried and convicted in the press even if you're 100% justified.
It's like having to use your firearm for SD and wearing a T-shirt saying "Kill 'em all and let God sort 'em out". It's the last impression you want to give the investigating officers because their attitude will color the prosecutors eyes. Everything will be taken into evidence as they investigate the murder because it will start as a murder investigation because they don't know what happened. Why make a steep mountain for yourself that you'll need to pull everyone over especially if they don't want to go there with you?? The message sent is not the one you ever want put out there. But again, range gun? Who cares?