Unitrade BK56 1c & 4c Centennial se-tenant pane of 10, scratches on back cover

Unitrade BK56 1c & 4c Centennial se-tenant pane of 10, scratches on back cover

Robin Harris, in his Centennial Definitive Series 1967-1973 book, pg. 313, suggests a premium of 3X cat value.

Unitrade cat. value for regular is $5.00