1864 (Sep. 28) Neunkirken Bezirk Arnsberg, Prussia (Westfallen) to Reading, Pa., folded letter with Neunkirken (9.28) boxed postmark and red "Recommendirt" serrated box h.s. with red crayon "14" silbergroschen prepaid rating (12 sgr. international rate plus 2 sgr. registry fee), magenta "Aachen 30/9 Paid 23 Cts." cds credit to U.S. and matching "Registered" crown h.s., carried by Cunard Line Europa from Queenstown Oct. 2 to Boston arriving Oct. 14, red "Boston Br. Pkt. 'Paid' Oct 15" exchange cds, Very Fine. Estimate  $300 - 400. Aachen used magenta color for a brief period from about July 1864 to January 1865. Its use on this stampless Prussian Closed Mail cover is quite uncommon and on a registered cover, rare. $0 (Image)