Maybe you can convince Revell into sending you another sheet? You can direct them to this site to look at the decals they're providing. If they're interested in improving the quality of thier offerings then they should respond.
As for the white M on the white theater band, my instinct, however unreliable, would have expected a black border around the M or a box out of the theater band on the real bird. Hope someone can dig up some references. Maybe inside that Signal magazine that Piet posted?