David Weaver
George uses O1, A2 and I know he's mentioned packing HSS tool steel to make carving tools. I think any W1 that he's used has been carving tools, because of its tendency to warp (as in, it creates more warpage on larger plane irons).

I know george has often mentioned making A2 irons at CW and sneaking them in the planes when the blacksmiths were passing 1070 steel on the craftspeople because it welded more easily than higher carbon steel (as in, they were pushing substandard irons on some of the folks to make it easier on themselves to produce them).

George has gobs of stuff to sharpen with that none of us will ever see, like precision diamond laps and other jeweler's and machinists stuff, but he likes A2 a lot in planes.