Ant. Berger's privately printed registry label in red anticipates those that Luxembourg used in the 1930s. Here we see it used on a registered cover from Luxembourg-Ville, May 30, 1886, to the Royal Irish Rifles Quartermaster at New Barracks, Gosport, England.
The oval transit marking on the front is the London registry cancel of May 31, 1886. On the back is the Luxembourg-Gare, May 30, 1886 transit, and the Gosport, England receiver dated June 1, 1886. A p. 12x12½ 50-centime Allegory pays 25c UPU postage for this 13-gram letter and the 25c registry fee. The red wax seal is still nicely intact.
Ant. Berger was, I think, a dealer or collector. I can't recall having seen the privately printed registry label before. This cover turned up at the FIP Show in Lisbon last year. It's a compelling registered cover in all aspects. It would have been a shame to leave it in the dealer's stock!