There are many portraits of the guard personnel at Mauthausen, and these are all on line.
If memory serves there were numerous photos of camp staff in the museum at Belsen, mind you that was back in the early 70s
This is not human beast, just beast
This is the only photo I've been able to find of Joseph Kramer (the camp Commandant) in his uniform and wearing his schirmmütze. As you can see, it's small and low quality. It's also the only photo of a uniformed SS man I can find from Belsen.
If you go to the Bundesarchiv in Berlin and find the SS personnel files from the former US Berlin Document Center, you will find many images. I believe said image you post is from this source.
I would love for the opportunity to do so, I've still never been to Berlin. I almost went this summer, but unfortunately I wasn't able to go in the end. Perhaps next summer. Is the Bundesarchiv a place where anyone can access such documents? I know a friend of mine has accessed period photos and texts at an archive in Berlin, maybe it's the same place.
The Bundesarchiv is not a place for the whole public. You must have a legitimate research project connected with some educational institution, but they also have a fairly noteworthy digital presence. But there are various ways to approach the issue, and you can be sure that many others have trod your path before you. That is, the historical interest for this small number of people in the SSTV who became the perpetrators of the holocaust is enormous.
Here is a collar patch of such a person, his name unknown to me, but whose clothing has somehow endured.