Source for Rounded Dumbbell Handles?

I got a used 3 to 50 pound set of Hampton hex dumbells. Their handles are shaped like this:

I like the shape of the grip area, and I need to make some bigger ones now. I’d like to go adjustable. I’ve seen threaded dumbbell handles with a crappy rubber sleeve that is shaped like this. But does anyone know of an all metal dumbbell handle with this kind of grip? (A rubber gripping area would be fine if it is properly fixed to the bar… The ones I have seen just float so they get off center and/or deformed by the plates clamped against them)

Thanks in advance.