I replied to another of your postings requesting German translation help. I am not a native speaker, although my husband is and I lived in Germany when we were first married. I am making an initial translation for you in case you don't get another reply.
The writing on the back of the photo is written in the old Suetterlin writing style no longer used in Germany. It is tough for most younger people to decipher. Here's what I could read:
Happy birthday wishes for your birthday, dear brother-in-law Anton, from your brother-in-law Willy ??? This photo was ???
Hopefully someone else can fill in the last few words, and correct me if I'm mistaken (especially with the word Schwager).
If you look closely, you can see a Swastika symbol on the button of the uniform.