After being 2 weeks abroad I found with the incoming mail-art this box from Jack Latteman (Cascadia Artpost) in USA. Besides the formal USA postage sticker he also included on the backside lots of own postage that looked quite good:
The surprise came when I opened the parcek and found this large and wonderful rubberstamp for the TAM-Archives, but for sure also to use it on outgoing mail:
Thanks Jack, for this wonderfuls surprise. It is very much appreciated.