Rebuild - 1976 Martin D-35 "Robert Earl Keen" guitar
In 1981, my wife bought for me as a wedding present Robert Keen's D-35. Lyle Lovett was waiting on a custom guitar being built for him by Bill Collings in Austin, Texas. Robert then had plans on purchasing Lyle's Martin D-18, and in turn sold us the D-35. 1970's Martins were kind of hit or miss. Herb Pederson had gotten in trouble with the company for coming out in Banjo Newsletter and complaining about his D-35 of the same year. The folk boom of the 1960's had tripled guitar production which resulted in some guitars going out the door that weren't quite up to snuff. This guitar, when I got it, had a "thuddy" quality with no clear sounds on the bottom end, sounding like the box was filled with whipped cream. Over the years, I have done everything from scalloping the braces, to replacing the braces, and replacing the bridge plate. Each stage improved the sound, but still left it lacking. In this final attempt to get good sound, I removed the top, scalloped the existing cedar braces I'd put in the last time, and went back to a production accurate bridge plate. My last attempt during which I installed a larger maple bridge plate to correct for a pretty substantial bowing on the top, resulted in a fairly clear top end, but no depth on the bottom.
The Process

Neck block with serial number Cedar braces, old bridge plate Pulling fret to get at neck joint Heating fingerboard to loosen from top Prying up fingerboard Inserting steam into neck joint
Neck off Martin part numbers Heating top for removal Prying top off Underside of top
Back showing water (possibly beer) stain Very strange red powdery stuff in a crack. Doesn't show from the top. No clue what this is. Old bridge plate - overly large and was killing bass response. Carefully reducing brace mass to encourage more response. Sheetrock to cover lateral shrink crack. Humidifying did not close these much.
Heat lamp jig for removing bridge (Didn't intonate perfectly.) Old bridge. I'll reuse after clean up. Go deck bars holding new bridge plate in place Binding had come loose in places Clamps for ensuring top and back match up Every clamp I own. I later modified my Go deck to accomodate this process
Binding going back on. This 40 year old binding is pretty brittle, but replacing it would make the guitar look too new. Neck going back on. Strap ensures very tight fit of heel against the body. Bridge clamps. I carefully measured scale length, and added a bit for string height at the nut. New smaller bridge plate of maple in place Drilling and reaming new holes through bridge plate.
Drilling and reaming new holes through bridge plate. Strung up Looks good and plays well; greater bass response and mids, intonates perfectly