The Real Modigliani

2010 AFP / Getty Images

For Marc Restellini, authenticating the works of the modernist Italian master is a matter of life and death.

This spring, French curator and art-world rebel Marc Restellini plans to release his long-awaited catalogue raisonné of Amedeo Modigliani (1884–1920), a definitive index of the Italian artist’s extant works. One such catalog was already published in 1972 by the respected critic Ambrogio Ceroni, but it is incomplete. Restellini has added about a hundred works to the 337 that Ceroni recorded a...