My machines were both mill/drills so the three axes were x, y, and quill. I used aluminum plate and angle for the most part. I modified the supplied scale covers to suit my needs. I mounted the x axis scales to the front of the machines using O1 flat stock and spacers so that the power feed and limit switches were still functional. The quill scales were the most challenging. On one, I used the depth stop qnd on the other a custom made clamp for the quill. I have a compplete set of SolidWorks files for the second, a Grizzly G0755. While not the same as your mill, it might give you some ideas as to how to proceeed. PM me if you wish to see them.