Unfortunately these things are extremely difficult to identify in photo's. You dont get the depth of field required to actually see them. I've 12 hours of video footage, which I'm trying to put into dvd form, but there is no substitute from actually standing next to them. I'll work on getting some stuff up, but I'll need help.
As for the stoneworking, the local rock is old red sandstone, and unsuitable for toolmaking. No traces of chips etc. The best description of these things is saucer shaped depressions, or small bowls in the rocks. Leave the photos with me, i'll get my mate to scan some of the more obvious ones and I'll get them up.