This cover features the two stamps, Michel 660 and 661 that were issued to commemorate the 5th year of Nazi Assumption to Power. There was also an official postcard P267 available. The cancel on this cover is one of 7 official cancellations used on the day (39th Jan 1938), this one used in FRANKFURT and inscribed "FRANKFURT (MAIN) | STADT DES DEUTSCHEN HANDWERKS".
The following cover also features the same two special stamps but this time it was cancelled in BERLIN.
COVER FROM GOSLAR 21st Feb 1938
This cover was sent from GOSLAR on 21st Feb 1938 and features a Michel 487 12Pf Hindenburg Medallion stamp.
LOCAL COVER BERLIN to VIENNA 10th Apr 1938
The following two covers were sent from Vienna to Berlin on 10th Apr 1938, the same day that Austrian's voted to become a part of Greater Germany. Both covers feature the special cancel used to encourage Austrian's to vote for the union and is inscribed "Am 10 April | dem Führer | Dein Ya" - 'On 10th April | The Leader | Your Yes!!'