There were three known Parker 75 pens made for use to sign treaties on nuclear disarmament between the USA and USSR and the documents were signed by the leaders of the two nations.:
Here is a dealer tri-fold tabletop display showing off the important role that Parker pens had in mankind's history, including the 1987 and 1991 treaties using 75 pens.
Each panel is approximately 18 inches wide by 29 inches tall and they are hinged together to make one unit that can be folded for easy transport as an oversized briefcase with a built-in handle.
This display was folds and snaps into a suitcase-like luggage. It was placed into an outer cardboard box and was made by Skyline Displays, a big vendor of exhibits in the USA.
As you can see from the side of this outer box, it appears Parker made 8 of these counter displays.