The first crack that I fixed was the one in the top at the neck extension. This was a 2 part repair actually, because the top had come loose from the neck block as well. I carefully pried the top away from neck block and used sandpaper to clean the joint. Then I glued the top to the neck block. The crack was quite wide and I couldn't get it to close up, so using my plane I cut a shaving of spruce and used this with glue to fill the crack. It turned out great!
The top cracks could be closed by applying pressure to the top, so i reached inside the guitar, and pressed the crack open. I worked glue into the cracks, then clamped a caul along the length of the cracks. On the inside of the guitar, I glued a couple small thin pieces of spruce to support the crack across the grain.
A couple of the back braces were loose, so I carefully worked some glue between the braces and back, then clamped pieces of wood across the back. That was enough to close up those gaps. At this point I turned my efforts to the neck (I'll show this in another post).