Each is 2.25" and each has a white metal back with fixed horizontal bar pin. First three carry name of maker on curl Imber, Chicago while the last simply has a Chicago union bug. First is likely the earliest and from the late 1940s with slogan "Studebaker's Really Rolling." Second references "Commander V-8." Third dated for 1951. Final shows ring of humans holding hands around factory complex with text "Citizens For Studebaker, Inc." Couple of exceedingly tiny paint marks mostly on the second, but overall condition for these lithos is Exc. with all being bright and glossy.