Yes- the function/form thing:
This guitar, and the others I do with the really weathered tops lurk somewhere in the middle there, more toward the form end of the spectrum. Though they are fully playable, and set up as well as any professional instrument, they are definitely not intended as everyday gigging axes.
They are really more of an art piece that can be played if so desired, and the ones I have done previously, with the antiquey hardware and such, are currently in an art gallery in Nashville.
This one is a bit different, and I'm not sure really where it's place is- the high end hardware is really kind of inappropriate in this regard, but I felt compelled to do it.
There is no finish at all on the weathered surfaces, so yes, it is a bit delicate, but not as much as you might think.
Beech is a hard, fine grained wood much like hard maple, and the weathering it takes on sitting out in the elements for decades is a fairly tough patina. It will flake off if treated roughly, but there is little danger of splinters, unless you are really getting amorous with the guitar, in which case, though I would not presume to dictate moral standards, I cannot accept responsibility for personal injury.
I have experimented with different ways of protecting the weathered surface, but any sort of finish really kills the look.
Best I have come up with is clear matte acrylic spray, like for charcoal or pastel drawings, but even that doesn't look quite right.
I have thought about the epoxy/bar top stuff like Wes mentioned, and I may try that, just to see what it ends up like, but it will be a completely different animal at that point.
I also do a different approach, on other guitars, with salvaged wood that is not really weathered per se, but has still developed a nice patina over the years. This looks really cool when sanded lightly to highlight the original saw marks, and then finished normally- well as normally as I ever do anything.
This method produces a much more practical instrument, though not the same as the old barnwood.
Thanks for prompting me to explain this- I have been meaning to come up with a good way of describing the various degrees of utility of the guitars I have been making. This is a good start, I think.