Hey Robin,

I'm interested as well.

Would you be intersted in casting a "round buckle" similar to this picture:

I'll take some close ups & do a little bit of measuring tonight and post them.

The buckle as an "indent" on opposite side of the pin to give the look of a brooch pin when buckled.
http://www.craftycelts.com/celtic_brooches.html

Cheers,