Tristan- Thanks a lot for helping out on the ID's.
I would say your right on Freiherr von Ebberstein. From the little I read he had ties with Heydrich and a interesting nsdap carrer.
Moving on to post a card. Grimminger looks to be wearing a 1929 RPT badge. I wonder if these were given out at the actual event and if this particular photograph was taken during that rally.
Also... is his iron cross with ribbon worn in a out of the ordinary way?