I was about to recommend the exact same thing. Epoxy granite is used by some world class machine tool builders.

I think an interesting modern take on the Gingery machine, would be a homebuilt machine tool; built from epoxy-concrete. Linear rails, servos, fly-by-wire controls with force feedback.

Machine form factor would be a la Mazak Integrex but much smaller and fits in a two car garage. Total envelope would be 8"x8"x8"; high spindle speeds w/ low depth of cuts. That should compensate for the total lack of stiffness :)