For 10 points, identify these valuable instruments, known for being created by a namesake luthier from Cremona.
One of these objects that was stolen in 2004 included accompanying items labeled "Harwood"and "Sartory." The Smithsonian museum holds one named for Samuel Hellier, while a flat knife cut distinguishes the Betts one, on display inside the Library of Congress. Joseph Curtin and Gregg Alf counterfeited one of that was given the name Booth. One named for the Duke of (*) Alcantara was stolen from David Margetts, a UCLA student, while recently used ones include the Davidov, employed by Yo-Yo Ma, and Mstislav Rostropovich's Duport, which both have this designation despite being cellos and not violins, the instrument with which the creator of these objects is commonly associated with. For 10 points, identify these valuable instruments, known for being created by a namesake luthier from Cremona.
One of these objects that was stolen in 2004 included accompanying items labeled "Harwood"and "Sartory."
Stradivarius [prompt on violin until "Davidov"]