I have a Fender 12 string that is hitting her 35th birthday. I used to get her gussied up at a shop, but he's moved to Hawaii years ago. Not sure what he did to keep her in ship-shape, or it's just the lifespan of a Fender (vs. a CF Martin), but the action is getting high, and the top is ever slightly warping (me thinks I have an impeccable eye on neck bowing, and can surely spot a dip where the neck overlays the top). Can I make few turns of an allen wrench on the truss rod, and be good again?... guessing it's letting up on the tensile and let it harken back to better/quicker action, but more/less figure out the top and bowing??? I've replaced frets before, and worked well with resonator tuning, so figure it can't be that hard, as I've never heard/seen of any instrumentation. I Google'd and with no luck, found nothing on how to adjust an acoustic and calibrate thereafter, and how to wait and so forth and measure/re-measure. This bird has spent some time in very dry and hot weather, and now sits at my beach place, often unheated and perhaps slightly damp for 7+ years. It's a beautiful and was once a well-dried out guitar esp. for a sub-$1,000 model, and would hate to see it on the south side of life given 25 yrs of it's tenure with me. Advice/pointers/websites appreciated. I've posted elsewhere if like-minds are interested in whatever anecdotes appear, I can update here or PM.