I seem to recall that the moon is a regular front-lit subject. So, use the sunny-16 rule giving 1/ISO in speed at f16. But, if I remember correctly, opening up 1 stop is better.

So 1/100s at f11 for 100 speed film, 1/400s at f11 for 400 speed, etc.

You can't get stars and moon detail at the same time. The moon is just too bright. So, either go for long exposures for the stars or short for the moon.

Matt