I'm a bit of johnny come lately on this thread- but I have a good excuse - a week in Cornwall.

Cornwall has a few circles with all the stones lying down but (as far as I known) no-one seems to be suggesting that they were ever supposed to be lying down - the ones I can think of are Leskernick south circle, and the Craddock Moor circle (I thought there were more but thinking about it I reckon it's only these two)