Nice to find embedded broach pins in the UK.
This elegant brooch pin come in two different lengths, 35mm or 55mm long.
You get two fine silver bases, and 1 x base metal pin and 1 x base metal catch.
The fine silver base screws are set into and fired with the clay. Add the screw-on pin and catch after firing, and secure with epoxy glue. Use pliers to correct length of pin if needed, sharpen with file and polish. For best results, drill a 3,5mm hole to set the base screws in and secure them with paste.
999 (fine silver) base screws, and base metal pin and catch. 55mm long pin.