[Madact]

If you want to split the difference between "ugly valve holes in the moon discs" and "taking the discs off is such a hassle", you could always use aluminium or metallised mylar tape over the holes (presuming the valves don't stick 'out' too far).

e.g. http://www.amazon.com/3M-Foil-Tape-3...5337158&sr=1-3
Amazon.com: Metallic Film Tape (Mylar) 1" x 36 yards Several Colors, Silver: Patio, Lawn & Garden