Isn't it necessary to protect the bed from abrasives? If it gets into the micropores of cast iron, there is no way to get it out of there, and it will lead to wear on the guides
Another great video by a master craftsman. You show repair work on a higher level than most people can comprehend. Younger generation machinest, mechanics, engineers, and management of such environments would learn a lot watching all of your videos. We are limited by imagination, but seeing videos like you provide opens the imagination to greater posablities. I am retired out of heavy industrial work of several disciplines, and have seen lots of very interesting repairs similar to some of your work. Keep up the good work, and keep the good videos comming.