>Come to think of it, I've seen very few pictures (drawings or otherwise) of stone circles that don't exist anymore. Winterbourne Basset springs to mind. . and of course the Sanctuary.<
Stukeley did a sketch of Winterbourne Bassett in 1724* and also the famous one of the Sanctuary where he shows himself looking out towards Silbury.
* http://www.themodernantiquarian.com/site/2616
Unless I'm mistaken the 1st, 2nd, 4th, 12th, 13th and 16th images in that link show a sarsen that was erected by local farmhands about ten years ago. From memory, one of the guys who helped stick it up there in the corner said they'd found it when ploughing that particular field and had just put it there because it looked good. Will try to get some more info from him this summer but the stone in question is a bit suspect (note its colour as well) to say the least.