http://www.travers.com/product.asp?R...1%3D53-014-635

These come in many sizes and with different mandrels, Merit bore polishers, just have to find a flex shaft. Maybe make one out off a plumbers drain snake, weld the mandrel on the end [which might crack on the spring steel], or make a mandrel that uses set screws to clamp on the snake. Insert the snake in a flexible tube like a hard plastic water tube to control the snake. Make "custom" lengths.