Deutschoth [today: Audun-le-Tiche]
The Hindenburg 'Luxemburg' overprints were valid for use in the Alsace and the Lorraine from 1 Apr 1941 to 31 Dec 1941. Likewise, the Hindenburg 'Elsaß' and 'Lothringen' overprints were valid for use in Luxemburg during this period. As of 1 Jan 1942, use of Reich stamps was required.
While philatelic uses abound, commercial uses of the 'Luxemburg' Hindenburg overprints in the Alsace or Lorraine during this 275-day period are scarce. Unlike collectors, commercial entities presumably had and used only the stamps overprinted for their region, but here is a contrary example!
12-Rpf. 'Luxemburg' Hindenburg Overprint
Deutschoth (Westmark) a
10 Nov 1941
in the Lorraine
Joh. Bapt. Bouche & Sohn
From the map at the top, you will see that Deutsch-oth [today: Audun-le-Tiche] is on the French side of the border, just a few kilometers from Esch-sur-Alzette. Thus, it would not be surprising that this furniture dealer (Möbeltischlerei) had and used a 12-Rpf. 'Luxemburg' Hindenburg overprint, as shown here, on a letter to the craft guild (Handwerkakammer) in Metz. Yes, I believe this cover is commercial. Many others in my collection aren't.
Now here is another example that probably isn't philatelic, although I can't be sure:
40-Rpf. 'Luxemburg' Hindenburg Overprint
28 Sep 1941
Klotzsche [by Dresden]
Field Post, of course, was free from letter postage. Thus, the soldier-sender from the 8th Battalion only had to pay the 40-Rpf. special delivery fee.
As the surnames of the sender and recipient are the same, this well may have been a soldier's letter to his wife or mother. Why a 40-Rpf. 'Luxemburg' overprint was used instead of a 40-Rpf. 'Lothringen' overprint or Reich franking is unknown. In any event, a sole use of the 40-Rpf. Hindenburg makes this cover attractive!