Richard Nixon Inaugural Display

Submitted by Craig: I have a article that i have been trying to find online for some time and have not been able to. It is made of clear plastic that has the Inauguration Seal inside of it along with a 3 cent National Capital Sesquicentennial stamp. Under the Seal it says the following: The Inauguration of President Richard Nixon and Vice President Spiro T. Agnew, January 20, 1973. The shape is a pentahedron; A triangular prism. Could you please let me know if you have seen one of these before. If you can help Craig by providing information please click on the comment button. thanks!