1883: Sunken Die Proof of the 3rd UPU overprint “UNION POSTAL UNIVERSAL PERU” in a horseshoe. Two sizes, printed in black on white paper, mounted on card (228 x 151 mm.), with “C.337” crossed out and “26058” alongside. Clean and fresh. Comes with unused examples of the three low values with the small type overprint (1-3 centavos) and a block of four of the 1 sol ultramarine overprinted with the large type. Also, a plate proof of the 2 centavos in a top marginal imprint block of eight overprinted with the small type and a cover which is a mixed franking of un-overprinted 10c and overprinted 2c. Very fine. Scarce assembly.
