Lot 60775 – 1/2d green, specialised study of the T22 control blocks

1/2d green, specialised study of the T22 control blocks neatly mounted and knowledgeably written up on 19 album pages, with twenty-eight items including control strips of 3, 5 and 6, and mostly blocks of six with one important block of sixteen, showing a wonderful array of overprint, watermark and other control variations, an excellent basis for study and expansion