I have removed and cleaned these delicate Medieval Alabaster panels, they are the consistency of soap.
No water can be applied when cleaning as Alabaster breaks down into Gypsum. when in contact with water.
They were moved from their original positions in the 19th century, the walls of Strawberry Hill were x-rayed to find their original 18th century niches.
I will re-install them in their proper place at a later date, when they will be distempered.