Cool. I tried the direct approach yesterday afternoon and went in! (am in Dorchster for xmas)
No carved stones on display sadly (did see an awesome carved phallus from Maumbury rings though) but they have a massive amount unseen. Unfortunately no curatorial staff are in till after NY & they are the only ones who know whats in the store building. They are apparently cataloguing the rest but its a long process.

I have a number to ring on the 9th Jan as apparently a Tuesday is the day to try...