Putting these together suggests that the moon needs about 1 to 1 1/2 stop more than "sunny 16 exposure", or about f/9 to f/11 at 1/ISO; this matches nicely with someone's suggestion of f/11 at 1/ISO!
If your deductions are correct, my D60 light meter must be out by a mile.
A full moon on a clear night, about half way between the horizon and the mid point in the sky, required a 90th sec at F8 and ISO 100. With this exposure, the histogram was not quite fully to the right. I could probably have used 1/60th without blowing highlights. On another occasion I used 1/30th at f11 with extender, with good results.
As I recall, during discussions on the accuracy of the Sony F828 ISO settings, it came out that ISO 100 on the D60 is actually about 125. (I hope I haven't got this the wrong way round). Using the reciprocal of the real ISO, my exposure would then be 1/125th at f5.6. In other words, a sunny F5.6 rule.
I don't know what the dynamic range of the film used by Ansel Adams was, but modern B&W film has considerably greater latitude than any DSLR. If I were using B&W film instead of the D60, I think I could probably use 1/125th at f2.8 without blowing out highlights.
If we use the figures Howard has quoted, ie. the f stop is the square root of the ISO when the shutter speed is the reciprocal of the luminance in c/ft2, we get 1/250th at F10 and 100 ISO, which places the moon in zone 5. Moving it to zone 7, gives us 1/60th at f10 and in zone 8, 1/30th at f10 which is pretty close to my exposure of 1/30th at f11 at a 'real' ISO of 125.
What am I missing?