Rhodan if you are just beginning to use Rhino I would suggest you try several different ways of modeling the part. I have found in my limited experience with Rhino there are sooooo many different ways to get to the same place.
For instance the thicker part, which I am assuming is the base, has a depth of .91" and a fillet that surrounds the part. There are at least three different ways to get that fillet that comes to mind. Fillet edge, filletsrf and then one I have never used is to build a curve where the center of the radius would be and pipe a tube around the edge then use either split or trim to get your fillet.
Like I said....there's lots of ways to get there. Try them all while you have some time.