In less than a decade, the Turin, Italy, custom car builder Studiotorino has developed an impressive stable of revamped automobiles, including ones based on vehicles from Mercedes-Benz, Maserati, and Fiat. It is Porsche, however, that earned the honor of being the first marque to receive the Studiotorino treatment, resulting in the company’s first series of production vehicles. The RK line, which comprised coupe and convertible versions of the 2005 Boxter and Cayman, ended production in 2008. Now, to fill the …