Its an Italian made bumper spoiler called "OSELLA". It took me a while to figure out what it was. It was on the car when I bought it, just like everything else on that car.
My first car was a 78 320i 4 spd stick, I miss that car. took a licken and kept on ticken. Seeing pictures of yours makes me want to buy another one. Nice ride.
Thanks for sharing the pictures