The mention by Johnnie Sunshine a couple of posts above, of the guitar with the zero fret far enough from the nut to allow a capo on the zero fret, is perhaps an innovation on the "tone-evening" concept.

Carefully applied, a capo could possibly simulate the finger on another fret more closely than the bare zero fret, and would allow you to adjust the capo to get open strings as close to fretted ones as your ear, fingers, and the instrument can be made. It sounds as if it would be a pretty sensitive adjustment, but with the right capo - using a spare finger salvaged from somewhere for the capo pad, perhaps - the effect might "be there" waiting to be tuned in and turned on.

Anybody wanna give Johnnie thea finger to try it out?

John