So in the file labeled " it's snowing and had nothing better to do" I add this:
I have my Lionel acela sitting on an aluminum extruded track shelf. It needed an end piece to prevent my acela from slipping off the track in the event of say an earthquake.
So I designed and am printing the 3D model above. I have a right side and left side ( only the right side is showing ).
The piece slips over the outer ends of the aluminum shelf.
The .stl files are attached below.