We reworked an old OKK VMC several years ago. When we bought the replacement material, they recommended an epoxy that we used. It worked great. Our process...if you wanted to know: remove all old material - CAREFULLY, clean well (solvent, then denatured alcohol), dry completely (hair dryer or hand torch), apply epoxy evenly, install new material, clamp/weight evenly (we made an I-beam that fit the material and machined one side flat to minimize the amount of distortion in the flatness of the new material.) After epoxy was well set, we used a die grinder/dremel type tool to carve new grooves in the new material (for oil dispersion). Be careful not to carve all the way thru the new material. The grooves may or may not be needed with yours, if possible - observe the old stuff before pulling it. As far as scraping the ways....you'll have to see what they look like. If there is minimal damage to the metal - they probably don't need to be redone - IMHO.
Hope this helps.