1927 - Volta, 20c violet ERROR OF COLOR and 20c carmine, with Express L1,25 blue, from "ROMA-CENTRO 25-4-1927" to the same town. One of the few covers known with the violet Volta. Cert. Diena, Sorani and Cert. finanziario Bolaffi 100% (Sassone 210A+210+E12 - € -)
