Here's the one I did for my P-51D skins a year or so ago. You can see my progression from a darker, duller metal to lighter and shinier.
Click for full-size versionI intend to fill in the blank with "Punky II" from the 339th FG someday - its got a red & white checkered nose band, red & white spinner, and a green rudder, and fills in a missing FG from the '51D stable. I have a couple more in mind but there are so few slots left. Doesn't seem right to fill it up completely.