Barry Guerero,
I must clear a thing: The oboist plays the guitar and the violinist the mandolin. I do not mean that substitutes oboe and violin for guitar and mandolin.
Clearing this issue, I have to say that the guitar part must be played by a serious classical guitarist, in order to have a decent good sound. This is the way Abbado, Bernstein, Haitink etc, does it-as we see in dvds.