c.1880s German Empire cover Berlin – Eisenach Saal‑Unstrut Railway, 10 Pfennig stamp

Original 19th‑century postal cover from the German Empire, mailed from Berlin to the administration of the Saal‑Unstrut Railway in Eisenach. The front bears a red 10 Pfennig “Deutsches Reich / Reichspost” stamp cancelled “BERLIN II”, with attractive old German handwriting. On the reverse are additio