This is a rare (200 issued) Canal Zone 46a, the 1c Balboa "Mount Hope" Type 3 Panama overprint issue of 1915/20, centered F/VF, though without gum but no faults. Part of the N in CANAL is missing, not that unusual as the Type 3 overprints are often light and indistinct as they were applied locally at the Mount Hope printing plant. Bright color. Hard to find NH as indicated by Scott catalog value of $375 if gummed (which this is not), still a great addition to a Canal Zone collection.