May 2021-2

In which color was the value overprint in Swiss currency (2 Rp) on the former 10 Heller stamp from Liechtenstein (temporary issue 1921)?

The first postage stamp issue of Liechtenstein in Swiss currency in 1921 (not the supplementary issue) were

The stamp of the cover of the month is part of a series of supplements to the first postage stamp issue. There are 8 stamps of 20 - 80 centimes and one stamp of 1 Fr. What is depicted on the latter (1 Fr)?