And here are two Luxembourg definitives for the thread. The first is from the second German occupation series of 1940, featuring 13 stamps from the 1926-35 Grand Duchess Charlotte set, plus 3 others. It is the low value 3 pf on 15c (Mi #17).
The second stamp is from the 1965-75 Grand Duke Jean series. It is the 10 Fr value (Mi #899y, Sc #572) issued on January 9, 1975.