Chiming in here. This is a red urethane rag joint that came with the Spyder project I bought. It was installed on the steering box but with no steering column attached, so it had never once been used to turn the car's wheels.
After replacing it with a proper rubber one and getting the steering shaft dialed in, I still had just a bit of play in the steering. I was about to make a tool to adjust the box when someone (probably @DannyP) reminded me to check the nut holding on the pittman arm. I found a big socket for that and a breaker bar and, sure enough, a bit of grunt moved it an eighth turn or so.
And that did it.