Many makers and manufactures will use binding made of plastic or other materials to accent the edges of the top, back, fingerboard and peghead. The celluloid binding on some instruments can start to deteriorate and crumble with age, taking on the appearance of a crazed puzzle. If there has been little to no binding loss I can sometimes flood the tiny crevices with adhesive to solidify the binding and preserve it as much as possible. This must be done carefully as the open end grain of the top and side may be discolored if the adhesive is drawn into them. If the instrument is in need of new binding I will usually yellow it to make it appear vintage and keep the original look of the instrument.
Cracks can spread and create even more damage over time.
And, once a crack has had the chance to accumulate dirt, it rarely goes back together without a noticeable line. If you are in the habit of cleaning your instrument on a regular basis and notice a crack, avoid contaminating it with wax, polish or other cleaners. D amage - Cracks that are too wide to simply be glued back together can be filled with a splint or very thin slice of wood that matches the area being repaired. It's important that the patch be made of the same wood, as different species of wood shrink and swell differently. This difference could result in a crack that forms a gap or reopens.