I have some ball handles to make, and there's a possibility of making more than two.
I looked at machining a form tool, but with tool steel, I don't think it'll last too many handles, and the 0-1 stock in the size required wasn't cheap!...
So I took a look at this
https://littlemachineshop.com/products/product_view.php?ProductID=2569&category=Yeah I could make it....I says....and the other voice said Yeah When!!! so I bought it
they have two sizes, but I don't regularly turn balls, and when I do, they're sub 3/4 and I usually interpolate and polish/file them.
I got this today, and I immediately dropped it in a tool holder, knocked the wax off the presharpened and mounted tool, and challenged a piece of brass.
I was pretty impressed. It's rugged for it's size, and it turned a nice little spherical end!
It came with instructions for use, which....I eventually read....

I'd say I think it's worth it. Glad I have it, it's nicely made, what's not to love?
The tool it came with is quite sharp. I would radius the tip of it for brass...but it's HSS and removable and they sell replacements.
Dave