Auction 309-320 - Great Britain 1840–1841 Europe & Overseas - Day 5

1850, selection of six used Archer Perforation Trial stamps, comprising three which illustrate perforation machine problems, such as off-centre, broken perforation pin - which comes with a RPL certificate - a long stamp which is caused by perf. comb adjustment, and three other examples, one which is matched with an imperf. of the same lettering, a mixed lot, very presentable and scarce assembly.