Leather covered? Is that a lead weight in the head of it?
Is Black Jack what you grandfather called it, do you know?
There’s bosun’s stick design that is similar, with monkeyfist knots at either end, a bit of lead in each knot. The handle is just coiled rope. Maybe a topping layer of light string wrapped all over. The sticks are usually finished with a thick maritime shellac/varnish.
Yes. As far as I know that's what he called it. A black jack
There are two more. One is a leather belt with a large overhand knot tied in it containing some kind of metal. I suspect it was taken from someone he brought back to jail.
The third is a very highly polished and used leather covered wood implement with lead inside the end. I think it was a billy but is much shorter than what I think of as a night stick. It was for providing a solid lick that would encourage submission. It was well used by someone. The leather is polished with use and the end has worn through exposing the wood/lead inside. I suspect a Deputy gave it to him after it had been in daily use for a long while during the 30's/40's.
It is about 10" long and of commercial mqnufacture. It is somewhat like the image below