Lot 31974 – 1916-23 1/2d yellow-green, 1d bright scarlet and 2 1/2d blue with SPECIMEN overprints type GB26, in mint nh marginal blocks of four

1916-23 1/2d yellow-green, 1d bright scarlet and 2 1/2d blue with SPECIMEN overprints type GB26, in mint nh marginal blocks of four (1/2d from upper left corner of lower pane, 1d from lower left corner and 2 1/2d left marginal), 1d with light gum bend, very fine and fresh, a rare and desirable group of positional multiples not distributed by the UPU with only part of a single pane (120 stamps) of each value released by the BPMA