There’s a ship with sails carved on one of the stones, along with other shapes (a knife or sword I think, etc), and it’s likely that the stones were plastered and painted, but all that vanished in millennia of rain.
It’s important to keep in mind that the monument was found by a new group each time Britain was colonized by someone new (and that has happened a lot), and reused. Also, during classic pre-Roman times there was seagoing trade all over the place, and tourists, and ya can count on those bastards to leave graffiti everywhere.
The whereabouts of the missing stones will be difficult to figure out. During the early 20th century, at another British megalithic site, conservation work was being done. One of the largest stones had tipped at some point and the conservators winched it back upright. As a consequence they found the well-preserved remains of a 16th century rich guy (he still had a coin purse which made the dating a snap), apparently he was having the stone hauled away for some project.
Thanks; didn’t know about the ship carving, either.
Speaking of sculpted stones, going to Crazy Horse tonight for the annual September night blast celebrating Korczak’s birthday.