It has one issue right out of the gate. There is undercut on the TIG socket weld! There is almost no room there for a weld bead.
The post has a sleeve in it that goes all the way down the shaft, and the base of the tool post obviously goes all the way to the plate.
The only way that I can think to rectify this is to put a proper socket weld bead there, and then machine it down to flush with the plate and flush with the shaft. This way, the top of the plate and bottom of the post would meet at a hard 90°.