United States 1822 Philadelphia to Netherlands London Forwarding Agent Stampless SFL

Stampless folded letter, with contents datelined "Duplicate / orig. for ocean via Hamburg", Philadelphia, October 19th, 1822, rated "10" in black, to Schiedam, Holland, endorsed (and subsequently crossed-out) "per Unicorn / via Liverpool", forwarding agent endorsement from the firm of Bainbridge & Brown of London, with c..s. transit backstamps, fine.