There is a similar species found only at the eastern end of the island, and near Camaguey, called Munroe's Sicklewing Eantis munroei which has a slightly different forewing shape in having a straighter outer margin than E. papinianus and with a barely discernible falcate tip. E. munroei also has more extensive silvery scales over the whole of the distal half of the underside hindwing.
Thank you Dayron for letting me use your photo.