These are Speedball Cutters that Kirbert has modified the same way that he modified the old Staedtler ones (yes, I have unearthed those, too, and will see if Kirbert still wants to modify them for me).
This is the #1 miniaturized cutter. The top of the cutting end has been ground down to allow for a much better view of exactly what (and where) you're cutting and a smaller tip to get into those really hard to reach places. Do not confuse this with the so-called .5 blades that some people pinch - these have not been squeezed to narrow the valley of the blade, just made a lot more versatile for fine work.
This is the #1 reversed cutter. Look at how the top of the V is angled back from the point. This is a fine blade for getting into tight inside corners. Shallow cuts are a must with this cutter, but it is a real help when carving letters. I had to get used to this angled blade - it's easy for me to bury in the carving block if I don't keep my cuts shallow enough.
This is the #2 miniaturized cutter. Just like the #1 mini, the top of the V has been ground down to give better control and visibility - just with a slightly larger tip.
Finally, this is a #4 miniaturized. Once again, the top has been ground down to give a shallower, squared edge for removing larger areas, while still allowing the visibility needed to control how close you want to get to the image lines.
I have a limited number of these to begin with, but if they look like they're going to be popular, I'll get another batch sent off to Kirbert for modification. I sort of wanted to see what people were most interested in before getting too many of any one modification made, so I'll be watching how it goes.