751709 Great Britain SG 489c certleelee5:05 pmSeptember 19th, 2023 751709 Great Britain SG 489c cert 0 SG 489c 1941-1942 King George VI 2½d. Top marginal block of 4. IIMPERFORATE (2 pairs). Unmounted mint. With Cert. AN EXCEEDINGLY IMPORTANT ERROR.
