>...Avebury maybe isn't a whole complex, it's the remains of lots of "temples" from different times - and the big ditch and ring are just a relatively modern, cheap, nouveau riche and rather vulgar add on that totally destroys the original essence of place....<
Interesting idea Nigel, and the Karnack Temple(s) complex at Thebes springs to mind as something similar.
We keep coming back to the lack of research at Avebury which, if instigated, would surely answer many of these questions. If ever a site in this country warranted an ongoing research programme Avebury is it! Incidentally (and apologies to those who already know) the Stukeley plan that you mention on page 45 of Neil Mortimer's <b>Stukeley Illustrated</b> is available as a facsimile from the Henge Shop in Avebury; the detail is excellent and it's printed on a good, light buff-coloured paper. The plan measures some 21x17 inches and for me is a constant source of interest and delight. In the south-east quadrant for example, Stukeley has inscribed (about several lost stones) <i>Demolish'd by Tom Robinson... 1700</i>.
A curse be upon the name on Tom Robinson.