Cartolino
Collectors all over the world use different catalogues. This conversion table can help you.
Search by S_xxxx for "Sanguinetti" catalog;
Search by F_xxxx for "Fada Unificato" catalog;
Search by M_xxxx for "Italien company Milan" catalog;
Search by L_xxxx for "Liebig company Antwerp" catalog;
Search by T_xxxx for "Tourteau" catalog;
Search by J_xxxx for "Jansens" catalog;
Search by G_xxxx for "Van Der Auwera 1954" catalog;
Search by H_xxxx for "Van Der Auwera 1977" catalog;
Search by N_xxxx for "Arno" catalog;
Search by R_xxxx for "Dreser" catalog;
Searching by words is also possible.
Liebig conversion table.