Embed the fine silver pieces with pasta on your silver clay.
Caution: Put a piece of tissue paper into the threaded hole so that it does not fill with paste or clay. Do not twist the closure in place after firing your silverclay brooch. Turn it until it stops, do not force it otherwise you will get a bump on the right side of your jewelry. Now turn the closure back to face it the right way, with a little glue between the thread and the pin will lock the closure.
It is also possible to solder the fine silver brooch parts.
Create the pin by cutting it out and pointing a new point with a file, for example, an agate pen or polishing needle, you can make the point smooth and harder.