I bought a used DG-300 from ebay recently, in great condition, but it came with some odd issues. The smaller 4 strings are intonated well, but the A string's intonation is radically sharp and the low E is radically sharp. The high strings have been shimmed up with a piece of ebony under that side of the bridge, but the bass side is still directly on the soundboard, and the low E has horrible buzzing up the neck. I'm thinking I just need a new bridge. What do you think, and if I need a new bridge, what are some quality options available?