David,
No double exposure, the balance of light, sun rising while the moon set balanced out the exposure. Actually, the moon moves rather rapidly at that magnification making stacking of any kind pretty difficult, unless you can shoot at 11fps of course. Next month the timing may be a bit better as the sun and moon will be rising/setting at the same time.
On another note, need an AF long tele for the S, really struggled getting this in focus. At least give us a tele convertor! Because of the temperature difference inside/outside, the focus creeped slightly as it adjusted to the cold so I constantly had to stay on top of the focus. Used the Eye-Fi card and iPad to check for focus as I shot, best tech accessory that I bought so far.