Not a fan of the vinyl holders. Bunch of holes in the boat, and they get dirty looking quickly.
For many years, I've used a piece of PVC pipe from Home Depot. Big enough around for the winch shaft and bit to go in. And just long enough so that when you pull the winch handle out of it, the bit doesn't get hung up on the bottom lip of the pipe. So, length of shaft plus half an inch.
You just cut the stuff with a handsaw, and the writing on it comes off with acetone. Clean up your rough cut with some sandpaper. I drill a couple holes about an inch from the top, about an inch or so apart, and do the same thing about an inch from the bottom. Then thread some cord through the holes to attach it top and bottom to a stanchion or in my case, the forward upright of the stern railing.
They don't need a bottom, because the grip portion of the winch handle keeps the handle from falling through. I don't recall the diameter of pipe I used, but it must be close to 3", so jamming the handle in there is quick and easy.
Bear in mind, I'm in Michigan, but I've yet to see one of these turn yellow from UV. And they look just fine. Nobody notices them. In my case, they're just a few inches from each of my Genoa winches. I should add another one to attach to my dodger supports so I could have a third winch handle for the cabin top winches for the halyards.
And, you can't beat the price.