Here's the map of my Extra from the race, with labels attached. To get rid of the squares on the nose and fin, just paint them the same colour as the background part
If you haven't got it already, I can highly recommend getting
FS Repaint from Abacus. Even if you just download the freeware demonstration, it lets you repaint the plane and see the results in real time as you're doing it. You can't save the repaint with the demo version but it does let you paint a square of colour and drag it all over the bitmap so you can see what each area does. Much of the Extra bitmap looks blank but actually very little of it is unused.
Gryshnak
Edit: Don't bother putting lettering down the side of the fuselage, the distortion in that area is terrible!