Abit KA7, I had one for 3 years. Excellent board, good overclocker. I could run my 600 at 744 without using a golden finger device. Tried it with the GFD and couldn't get it any higher. Now my brother is using that board.
Back on subject, I wouldn't worry about the crusty stuff if it's not affecting anything. If the board is still running good with blown caps, I wouldn't go messing with it! Why go looking for trouble?