Note that the bed section has been given a proper footing. The bed has been accurately milled, removing all wear and score marks. It is usually a good idea to scrape a milled cast iron surface to knock off the mill fuzz, but if an 80 RMS surface or better can be achieved a good stoning is all that is necessary. Leveling the bed is a crucial first step. If you mold to a twisted surface you will replicate a twisted surface.
