The Witch who Forged a Monet

Mass-produced prints or original masterpieces?
Someone's watching Penzi and Felix investigate. Someone who'll not stop at murder.
At long last, white witch Penzi and her sidekick Felix, the shapeshifting leopard from the Middle Congo, find themselves with the time to return to their task of sorting out the contents of the brocante or antiques shop next to their house in Beaucoup-sur-Mer. Months ago, they cleaned and tidied up the place, disposing of the obvious dross. Now, it's time to arrange for the valuation of the paintings and sculptures that remain.
The assessor from the Louvre in Paris tells Penzi and Felix he's being shadowed. Once again, Penzi and Felix deal with the echoes of the unhappy history of the region. Someone knows more about the provenance of the artworks than he does. Who and why?