Sorry for coming so late. If you mean this particular thread: http://earlyguitar.ning.com/photo/fabricatore-in-pieces?context=user (can't think of any other one ...), where I did express my doubts, not about the Fabricatore guitar but the presence of such diagonal braces in some surviving baroque guitars which are indeed not original. The diagonal brace in your Fabricatore, however, looks original to me: a few Fabricatore guitars (I suppose of different makers sharing the same name) that I came across with all had similar bracing patterns. I'm far from being an expert on them though! The only difference I can see with your guitar is the lack of paper that would cover all the internal surfaces of both the back and sides. To me this feature looks like the most mediocre one that I have encountered in early guitars (i.e. totally counter-intuitive from acoustical point of view), although not that uncommon in 19th century Neapolitan mandolins as well as in some Franciolini's 'fakes', so they didn't seem to mind.