1870
Specimen 1899 1a. to 4a. overprinted "ULTRAMAR" in blue or violet, without gum, and 28a. overprinted "SPECIMEN" in violet, unmounted mint. (5)

细节
Specimen 1899 1a. to 4a. overprinted "ULTRAMAR" in blue or violet, without gum, and 28a. overprinted "SPECIMEN" in violet, unmounted mint. (5)