Here are the plans to make your own heated base for a star or magma sizer. The plans are 1:1 on the base so you can use the plans as a template, just measure a couple dimensions to verify first. The nut piece for the ejection tooling can be made from all thread and a custom nut which can be easier to make than the piece on the drawing. If you are just making one the material will probably be simpler and easier for just machining it as one piece. A Uni bit can be used to debur the big tapped holes in the base quickly and easily, I usually debur first and then tap second. These holes also need to be tapped straight for the removal tooling to work.
Videos are on youtube, just search out Marshall Reloading