Center seam top crack :: 1996 Martin HD-28

I'm using magnets along with low-tack drafting tape to lay out the top bracing.  Once I find the braces, I can fit the cleats that I need to install in order to reinforce this open top seam.  Below I'm using TJ Thompson's top crack corrector jig (available through Stewart MacDonald) to install a radiused cleat that runs the length of the crack.