begins with mint CO1-CO7 and CO14 and cancelled to order CO1-CO7 with shade varieties, continues with overprint varieties including "O" of "Official" over "N" of "Panama" (CO1.2a, CO2.2a, CO3.2a, CO4.2a, CO5.2a, CO6.2a, CO7.1a), "O" of "Official" over second "A" of "Panama" (CO1.2b, CO2.2b, CO3.2b, CO4.2b, CO5.2b, CO6.2b, CO14.1a), first "F" of "Official" over second "A" of "Panama" (CO1.2c, CO2.2c, CO14.1b), and "L" of "Official" over first "A" of "Canal" (CO7.1d, CO14.1c), followed by broken overprints, CTO varieties, shifted overprints, and more, generally fine to very fine, a spectacular collection for the student of this issue