5rin koban X ... imperfs

these items were reviewed in JP some years ago, and since forgotten ... part of 1963 kelleher sale in the USA. being imperfs, they were described as proofs ... and appeared in seven colour trials ... a proper term is essay clearly, both are 16 petal kiku as the known spiro sheets ... characteristics reveal they are closer to redrawn plate or retouched matrix ... MXC2 chiossone did send graphics to the Boston Expo, year ? can anyone provide more information on this series ... Boston and Genoa were "twin cities" ...