Design is always a difficult and personal choice. I find once I start, I can't stop getting ideas, then don't know which one to pick.
So....I make a few drawings, then make cardboard mockups of the ideas. Hit them with a bit of colour to help match.
From there, it's easy to customize your existing pickguard or any future ones as you have templates ready to go.
To me, your idea looks great but take your time to find something with which you are happy.