This is a re-implementation of the DIN rail clamp in OpenSCAD. The polygon was designed with pencil and paper, it can be simply imported into another design as:

polygon(points=[[0,0],[0,41],[17.5,41],[17.5, 34], [13.5,37.5] ,[12.5,37.5], [12.5,3],[2,3],[2,2],[14,2],[14,5],[18,1], [18,-4],[12,-4],[12,-2],[15,-2],[15,0]]);

The STL is for a small SSR board of 55x53 mm with screwholes on 1700 & 1800 mil distances.