KUT 1949 KGVI 40c Imperf Printers Trial with Ceylon, Gibraltar

1949-52 KGVI 40c Crowned Cranes IMPERF PLATE PROOF / PRINTER'S TRIAL: Block of four partial impressions on greenish buff paper with additional overrun of GIBRALTAR and CEYLON values, also on reverse. Interesting piece presumably from the printer's working proofs, an unusual combination for these.