Vintage 1985 Rimini unique black blazer. Size 12/14

Vintage 1985 Rimini black blazer. No size tag but thinking a 12/14 so look at measurements in photos. Fabric tag also in photos. This is a unique blazer. I can't figure out why the fake shell top underneath unsnaps only on one side. I am assuming you can tuck it and wear with a different shell underneath. Again please pay close attention to the measurements. Pricing to sell. Also beautiful rhinestone button.