A blackwork biscornu

This biscornu, just like the one I posted previously, will not have sarp corners but nice wavy sides.

I marked with arrows where the pieces should meet in the middle, green arrow with the green and red with the red. I hope it is clear.

As for the stitching, I drew it in one colour but I am thinking of stitching it either in some multicolour thread or stitch some parts with metallic.