Quote Originally Posted by tappo View Post
the plate held by a Phillips-type screw instead of the normal screw/ejector (which is not needed in trainers) will immediately turn the noses of purists, but before making hasty judgments let's move on for a moment.
I wonder what thread pitch the Phillips screw is? I wonder if it's machine and non-gun thread?

The head looks like the later straight cross of the JIS Phillips and not the original Phillips of the 1930s with a slight open center. That might date the mount as later?