My dad has an old pre-teens Gibson A with a sinking top. I visited him over the weekend in Phoenix (hot and dry) and saw increasing damage to the instrument. BTW, it is going to Iowa for safe keeping. The top has been caving since he bought it, (the top is not broken or cracked behind the hole) and now the finger board and top seam above the oval hole have cracked open. Plus the seam around the back is now visible almost all the way around. I removed the strings and bridge and checked for a loose brace, but could not determine if the brace is loose. It doesn't seem to be. The top is just caving from the bridge force. My question is: Will the top return to normal or can it? For sure I will have to replace the finger board and fix the top crack. I may go ahead and remove the back to be able to clean and reglue. If the top is salvagable?, I would consider X braces or replacing the transverse brace. Is there a thread on installing X braces like this? I have seen Gails thread on the top brace repair. But I'm not sure if that will fix the sinking top. It looks like the arching is collapsing outside of the brace.

Steve