1909, 15k perforated trial color plate proof in light blue (81P), o.g., never hinged; few very faint perf tones, mentioned only for strict accuracy, Very Fine. Zverev $750.
1939 Aviation Day, 1r brown, blue overprint double, used, top right sheet corner margin single, v.f., signed Goznak. A unique positional piece from the only one sheet of double overprints printed, all cancelled "Leningrad" (Zagorsky 605Tb) - Cat. Val. $1,900
