This shows up in the major catalogues, sort of.
Gibbons lists a blue surcharge, only, for this stamp. (Unless I overlooked something, based on what I'm about to type, below...SG
does list a black variety for the 1d.)
Scott
Classic lists a blue surcharge as the main catalogue number, a black surcharge as a variety (but with no values for mint or used), and a note that counterfeits exist of the black surcharge.
Yvert lists a blue surcharge, with a black surcharge as a variety at a 5x premium.
Robson Lowe
Empire in Africa lists a blue surcharge, with a black surcharge as a variety. They say that 100,000 of this and the 1d were overprinted, which is far more than any other denomination. They also say that the single-ring cancel should be 29mm in diameter, and I wonder about yours.
I have no special expertise about this stamp, so take all of that with a grain of salt; all I know is what I read in books.
Posted 12/10/2017 09:28 am
