This is for a vintage pin from the 93rd Convention of the International Typographical Union, which I believe took place in 1946 in Atlanta, Georgia. The union was founded in 1852, and I believe the first convention was in 1853. This pin was for the Sacramento delegate from Local 46 who is identified on the paper insert as Carlo Costamagna.  Pin has a small blue ribbon connecting the two bronze-colored metal pieces which reads "DELEGATE" but the letters are fading.  There is aqua-ish colored corrosion to the backside of the top piece of the pin (see picture).