A Canosan figure from an old Japanese collection

I have not commented much here about Japanese collections of classical antiquities (but see the Miho Museum). I was thus intrigued to see a Canosan terracotta figure of a woman (lot 110) among the pieces on offer at the June 10, 2010 sale of antiquities at Christie's Rockefeller Plaza. The 3rd century BCE figure is valued at $5000 to $7000. She is "holding a mask of Medusa in her left hand".

The collecting history is simple: "Japanese Private Collection, 1980s".

Who was the original vendor of the piece? What is the name of the anonymous Japanese private collection? Who is the present proprietor?

Canosan figures are usually found in Apulia in southern Italy.