Be aware that the yellowish/beige Solartex that most people use on EIII models comes in two version: Antique and Linen. The antique is semi-transparent so you'll see all the underlying structure which isn't so great if it's non-scale structure or wood where it's supposed to be open structure. The Linen Solartex is the same color but completely opaque.

I'd recommend that you cover the whole thing in Linen Solartex then paint the colors and markings with custom matched latex from the hardware shop. Then give that a final fuel-proof coating with Nelson's Flat Clear.