I have a set of 4 universal joint assemblies to sell as a lot. These are for PTO and other rotary motion applications. These have light surface rust from storage and are greasy looking, but I am not sure if they were ever used. I think grandpa bought them and just stored them away. They all operate freely. They take a 3/4” shaft with a keyway on both sides of each universal joint. Hope it helps with your old tractor or jeep.