That is awesome Ghost Knapper,
If you are looking for the deep C-bulb notches, I would suggest using the edge of a coarse stone biface as a punch. You can put the edge of the biface into the notch, and rap the back edge of the biface. It is better to use a really coarse grade biface, so as to minimize breakage of the biface. Also, I think that a small ovate biface works well for this type of punch. If the shape is ovate, there is less risk of burinating the tip, with a sharp blow.
I believe that there is another type of punch, in the archaeological record, that was used for the same effect. It looks like a small peg, with a beveled end that looks like a blunt screwdriver.
I have not yet tried the latter tool. But, I have seen it in archaeological reports, over the years.
Ancient Tech