Here is the original DWG and STL. I imported into aspire as a model. For a one inch piece of wood, I rotated the model up, and stretched it to around 18 inches. Then I selected to max height the object at about .95 inches, and chose to delete the remaining model - making the flange area shorter than the original model - with just a bit of a straight edge all around. I could also share the original aspire file if anyone is interested…
NukaCapNoText.dwg (534.0 KB)
NukaCapWithText.stl (1.1 MB)