I have a 1970 Gibson J-50 Acoustic that recently has been buzzing on me. There is no visible damage to the neck, i.e. no cracks or reglued parts anywhere. So, I took it to a friend that works on guitars. He put a new bridge saddle piece on it which corrected the buzzing, but now there are intonations issues in certain regions on the neck. Sometimes when the guitar sits its sound fine everywhere, but after one starts playing and tuning the instrument its starts into playing sour on either high regions of the neck or in the first three frets.

Any suggestions as to what might be up with this problem and how I might correct it. The friend I took it to said there is nothing he could do about the intonation issue and he didin't want to fool with the neck.

I absolutely love the tone of this guitar. And would do almost anything to it to get it back as a playable instrument. I'd even consider puting on a new neck if that might help.

Please respond if you know what might be some of the causes of this intonation issue; and, if you might have some advice as to how I might get the instrument restored to its prior condition.

Thanks!