Thanks Shipto, I've been away from metalwork for awhile but expect to resume when the weather here gets cooler. Too much time spent working on the house, and occasionally fishing when I get a chance this summer.
Anyway, yep, a tool grinder (or sander in this case) doesn't have to be complicated or costly to provide a fair range of sharpening angles and slide movements. With this one, you do have to replace the sandpaper occasionally, but it is very inexpensive, and presents none of the dangers of a grinding wheel used for side grinding, or the cost of a cone wheel, and presents a true flat surface to the tool.
I'm not at all dissing beautifully designed and made tools like the Quorn, and would be happy to own one myself, though not to build one -- many more machine tools I'd prefer to build before a complex cutter grinder, and especially would enjoy making a gear cutter, like the one I've mentioned before as published years ago in ME. But even that would have to wait for the final completion of my homemade lathe, as envisioned.
So I'm in the same boat -- things planned, but no time at present. Fall will, I hope be different!