Hi Gerald,
This looks like a valvecover built for rear-engined cars, like the 1000TC. A112 Abarths have the oil-filler cap on the other end of the valve cover.
When fitting an A112 engine in the back of Fiat 600, you will notice that it is quite hard to reach the oil filler cap (because it is very near the firewall/rear bench). That's why lots of people with Abarth 850TC/1000TC's have normal (pressed steel) valve covers from Fiat 600's or 850's fitted. But some parts dealers also offer modified Autobianchi covers with the oil filler repositioned or completely newly moulded valve covers.
Could this one be from.........Berni Motori?
great for a 1000TC!
I hope this helps, Alex