Also if youre cackhanded enough to break a split style die the wee bits left can also be made into chasers. I have some very old hand chasers that often get me out of trouble although I've only hand chased in brass for old scientific instruments.
That sounds interesting, old instruments. I found something called a Henrici harmonic analyser in a bin. It was in bits and I didn’t know what it was when I found it. It is kind of related to what was my job (noise and vibration) so that was nice. If you type that search string into youtube you’ll see a short video of it doing its thing, resolving Fourier components.