When I ordered my 15/6/1, I specified no logo. I just don't like logos on my cabs. The builder had no problem with this. In fact, I can't think of a single reason why any manufacturer or designer would prevent you from covering or removing the logo. It is, after all, your cab. I don't think you are violating any copyright laws by doing this.
Basses: P/J F'less, MMSR4 Classic, 60th Anv P, P5, Jack Casady
Amp: ShuttleMax 9.2, FearFul 15/6/1