1852 - 2b bluish grey in mixed franking with Kingd

 1852 - 2b bluish grey in mixed franking with Kingdom of Italy 20c on 15c light blue, 1st type “horseshoe', both cancelled with dotted numeral “35' from 'città DI CASTELLO 4 GEN 67' to Rome. Initially taxed, then cleared as the inspector considered the franking valid. Splendid and rare. Signed by Alberto and E.Diena, Colla and Manzoni certificates (Sassone 3Ab + Regno 23)