I picked up this little trick and specialized shop made tool (fixture) from my long time friend and “go to” vintage repair luthier in the San Francisco bay area, Larry Cohea. The problem of  how to clamp in a cleat on a crack or seam separation repair where a normal clamp won’t reach is handled with this little devise. What I did what cut an ell shape out a solid piece of curly maple and attach an old guitar tuner to the outside of the vertical aspect and the tuner shaft protruding through a hole drilled to accommodate the tuner shaft. A thin piece of leather was attached to the bottom of the horizontal aspect along with a small hole drilled through that lined up with the string hole in the tuner shaft. How the gizmo works is a small guitar  (or better yet an “E” mandolin string) is poked through the crack or separation in the spot determined for the cleat placement. The string is then carefully threaded through the hole until you can fish it out through the instrument sound hole (or “f” hole).   A small hole is pre drilled in the cleat which is threaded onto the end of the string followed by threading on a ball end from an old guitar string. A knot is then tied into the remaining string still protruding past the ball which will act as a suspended clamping caul if you will. A small dab of Titebond is then placed on the cleat’s inner surface and whole shebang is then pulled taut from the string end  still protruding from the crack or separation area. Grasping the string in a tight position, it is then snipped off 2-3″ above the instrument surface and that remaining is inserted through the hole in the clamping fixture and into the tuner shaft. All you do then is start winding until it’s good and tight.  An advantage of this type of repair is that you have a better chance at of wood grain lining up in the original orientation and the cleat(s) will stabilize the crack/separation to prevent further separation. The instrument in this picture was a vintage 1922 Gibson F-4 in the shop for repair/restoration.