Neat - I would recommend one change, instead of using the corner of the bench grinder wheel to groove the base, use a dremel cut off wheel or a 1mm cut off wheel on an angle grinder. I reckon more control and a nicer groove.
Further to Blog's excellent how-to on using the endmill grinding jig/surface grinder linked to above, here's a few pics of my cobbled up rig.
I have the same jig as his but no surface grinder. I modded a HF carbide grinder, a $40 Chinese x/y table, a Grizz mill vise rotary base and some scraps to grind the ends of endmills. I drilled & tapped 2 holes each in the 2 flats of the jig so it can be bolted to the adapter assy. I drew it up in CAD to figure out where to put the holes so the endmill would end up in the same spot after changing positions of the jig.
I haven't used it much due to gashing difficulties and the clouds of abrasive dust from dressing the wheel. I will get back to it when I save me pennies for a CBN wheel.
A cheepo spindexer fits onto the x/y table for misc grinding tasks as well