For this stamp issue I created what is probably one of the most precious things in my entire collection: on a Sesame Street card with the US stamps of 2019 and special postmark I also put the German stamp and got a special postmark for that one as well.
On matching Cards with Special Postmarks:
Prepaid Cover:
First Day Sheet:
"Erinnerungsblatt":
"Klappkarte":
"Übergabekarte":
Used on a Card:
Postcards: issued by the German Post:
