PC 37 showing
PC 37 was designed by Ludwig Kurz in Frankfurt and printed by Pierre Bruck in Luxembourg in a quantity of 30,300 cards. Issued on November 17, 1879, two varieties are known: on the first type, the distance from the Coat of Arms to the first address line is 8.75 mm; on the second type, it is 11.50 mm.
The example shown here with the cliché inverted is the first type. There is no mention of it in the literature I’ve seen. Who knows more about its origin?