Inscription
upper left, in brown ink: N° 4 ; upper left, in brown ink: 16 / [illegible]0 [underlined] / 00 / 32 [underlined] / 3[illegible]6 [all upside down] ; upper right, in graphite: Principio ; lower left, in brown ink: [illegible] [crossed out in brown ink] ; lower left, in brown ink: N [underlined twice] ; lower left, in graphite: 755 [underlined] / 430 ; lower right, in graphite: Fine ; lower right, in graphite: 755 / 430 / 1/6 ; VERSO, upper center, in brown ink: t [shape of a cross] ; upper left, in graphite: [illegible] ; upper left, in graphite: osss ; across bottom, in brown ink: [long series of numbers, sideways] ; lower center, in brown ink: [illegible, masked] ; lower right, in graphite: [series of numbers, upside down] ; lower right, in black ink: 5 [sideways, circled]