RARE WW1 AEF 5th V \"Victory\" Corps Isorel Masonite SSI Enameled Insignia Sign For Sale

This sign shows the shoulder sleeve insignia (SSI) adopted for the US Army V (5th) Corps during WW1.
YOU WILL BE RECEIVING THIS SIGN ONLY, THE SET PICTURE IS FOR INFORMATIONAL PURPOSES.From a nearly? complete set of signs that are shown in the third picture. This set consists of each of the shoulder sleeve insignia used by units from the 1st world war, and are a very hard, glossy paint that I am assuming is an enamel on a confirmed Isorel board painted black, and measures 12 x 12 inches (30.48 cm). They are separated by that thin black paper packaging so common in that era. I am certain that it is Isorel by the cross like pattern of the pressing on the back which matches the Isorel pattern exactly. Isorel was the precursor to Masonite, which was not patented until 1924 and did not begin mass production until 1929. This set was likely produced some time after the war as most units did not have an insignia until then.
About the set:
This is obviously a very rare set and I am confident that it was issued by a significant organization, maybe even the US Military given the quality of the signs. I have had speculation on what they could have been for and it has been suggested that they might have been for a veterans group, but I think that they might have been used more for design purposes, possibly by a company that was in the business of supplying the newly adopted insignia patches to the various units in the US Military. Each of the 85 signs in the set have a hole on the top and bottom of the sign which I believe would be used for mounting, and they appear to have been extensively used. I will be offering each sign for sale individually so please be sure to stay tuned to my other listings as these become available.
About V Corps:
V Corps was a regular corps of the United States Army during World War I, World War II, Cold War, Kosovo, and War on Terrorism. It was officially inactivated on 15 September 2013 at Lucius D. Clay Kaserne, Germany.V Corps was organized 7–12 July 1918 in the Regular Army in France, as part of the American Expeditionary Forces. By the end of World War I, the Corps had fought in three named campaigns: St. Mihiel, Meuse-Argonne and Lorraine (1918).The corps\'s shoulder patch, a pentagon whose points lie on an imaginary circle 2 1/8 inches (5.40 cm) in diameter whose edges are white lines 3/16 inch (.48 cm) in width and whose radial lines are white 1/8 inch (.32 cm) in width, was approved on 3 December 1918. The triangles thus outlined in white are flag blue. The pentagon represents the number of the Corps, while blue and white are the colors associated with Corps flags.shlf