I have this very nice tool set from Crown, and I like to use, for very fine details, a tool holder than can hold a shaped HSS tip.
So I made an extension to the set, trying to mimic the Crown design, here it is, just below the box:
It's made of mahogany, stained darker, a brass sleeve, and a mild steel tool holder, with a brass knurled set screw.
It holds a 4mm HSS bar. Here, this is one of my favorite profile, a kind of skew with oval tip, very useful.
Here, the other end of the bar, diameter reduced to 2mm, same shape.
And here is the kind of cove you can make with this tool, on boxwood. Take care, it is very small, it is a close shot.