Auction 333-341 Nigeria, Cameroon, Sudan & Worldwide Postal History - Day 4

1857 (Apr 1): Cover to Amsterdam, franked with 1852 6 baj. black on greyish-green and 8 bsj. black lower right sheet corner pair, cancelled by diamond grid and postmarked Senigalia, "2" in manuscript denoting the letter as being within the second weight class and underfranked as such, with "insuffisant" written alongside adhesives, double 55 (Dutch cents) penalty due by recipient, indicated by "110" in black, no credit being given for the pre-paid portion, red French entry cds on obverse, Amsterdam arrival backstamp (8 Apr), light filing fold crossing the 8 baj. pair, otherwise fine.