The bridge had started lift on this Guild 12 string. I wanted avoid removing it entirely ands tried to work glue into the opening with a very thin spatula and also relying on capillary action to suck glue in. It took a couple of attempts but worked really well and the bridge is now stable.
The owner complained that the guitar didn’t play well and on inspection it was clear the frets needed levelling. I also lowered the saddle.