Grasp

As I made my way through the City this afternoon on an errand, I passed this strange bit of decoration. Just what is the object in the hand?

The arm appears on the railing around the tomb of Sir William Rawlins, a sheriff of London in 1801, one of the wealthiest members of the Worshipful Company of Upholders (a fancy way of saying that he was an upholsterer), and a benefactor of St Boltoph without Bishopsgate (where he is buried).

Perhaps the hand is clutching some sort of upholstery tool, or . . . ?