I use my Domino 500 a lot and the two mirror finish surfaces have accumulated small scratches over several years to the point where it is becoming difficult to align with pencil lines on the wood. Is there a recommended way to buff these up? Barring that, can you order new ones? The parts diagram seems to suggest you can order the fixed part for a ridiculous price of $184 but not the moveable part. What's the actual deal here?