I have what could be considered a "vintage" Guild 12 string. My concern was the modification to the intrument. I went to Elderly Instruments and after much investigation I settled on an LR Baggs Dual Source. This has a ribbon transducer as well as an internal mike. You can mix the two from a countrol that mounts on the soundhole. The pickup handles my needs very well. The only modification to the instrument involved installation of the endpin jack. If I had to give you a drawback, it is that the controls are very small. But overall I have been very satisfied and can get a nice warm sound out of it. It cost me $275 installed.On my 6 string I use a Seymour Duncan Woody soundhole pickup. It works fine but is not the best solution with regard to sound.

BTW, does your name imply that you are from Kalamazoo, Michigan? I live about 40 minutes north of there. I would be happy to stop by and show you the guitar and you can see for yourself. I am in Kalamazoo several times a week.

All the best,

Mick