Cover from LA COLORADA with oval firms handstamp on front franked with 1914 10c pale blue & red 'Sonora Seal' issue (SG S36) tied by fine strike of O.P.A. No. 901 F.C.T.A.P. cds dated 16 ABR 1914. (Travelling post office on the Torres - Minas Prietas line). Addressed to HERMOSILLO with arrival cds on reverse.