Lot 71504 – An album page study of the 1966 British Birds 4d issue multiple colour shift variety

1966, British Birds, an album page illustrating the 4d issue, with a mint n.h., se-tenant right marginal block of four showing the multiple colour shift variety, also a block of four mint n.h. with the shift in greenish-yellow and a mint block showing horizontal bistre line above main twig with a normal block of four for comparison (wrinkle top right stamp), a highly visual presentation.