There is no real specific alignment in my opinion at Calanais I, at least not say with a stone in front and/or some specific horizon feature
Gerals Ponting seems to think differently:http://www.themodernantiquarian.com/forum/?thread=34224&message=417234&offset=25
"Unfortunately, Lewis cloud covered the moon about half-way across its transit, and although there was a slight glow in the clouds around 2.15, the moon never reappeared for the moonset among the stones."
I believe Gerald and Margaret saw this 19 years ago.