I've owned this Gibson 12 string since the fall of 1985. It has a very strong sentimental value to me. Sadly in 2005 the top collapsed and I destrung it in the hopes that it could be repaired.
On April 28, 2010 I took the old Gibby to my guitar repair class in Stratford to see what we could see. Spent all night chasing ghosts and couldn't locate the damaged brace. I got totally frustrated and put it away for a week. On May 5 I found the cracked brace at the opposite side of the soundboard, so we glued it up and were off to the races.
The end result was that the top was flatter than I've ever seen it. (The brace must have been a problem from early in the guitar's life)
As I looked at the neck, I realized that there was a slight hump about the 7th fret so out came all of the original frets, I sanded the hump out and smoothed the neck, then installed a brand new set of frets. They were all leveled, edge dressed then polished to perfection.
Ever wonder why a Luthier will charge between $60 and $100 for a 12 string nut? Well I'm about to reveal the secret.....It's because it takes as many as 4 trys to cut the slots without having the divider between the string pairs splintering out and ruining the nut!
The only thing left is to maybe replace the saddle with a slightly beefier one. Though having played it for a few minutes I think it might just be OK. 3M final finish brought the old lacquer back some lustre.