i am going to purchase a "Nelson" table made in the republic of panama for about $200. (4 1/2 X 9). the quality of slate is not that good but there are no other choices here. i have played on them for many hours and the slate has imperfections. (areas that are not perfectly flat). what cloth would you suggest to "smooth" out the bad areas? also, can i replace the rails with a better product or have to use the same bumper?