Just for the record, 1970 wings were also factory installed on many early built 1971 cars, I've seen cars with build dates well into November of 1970 wearing factory installed 1970 wings. So, that being said, "technically" either one is correct for 1971, but only the early 1970 style would be correct on a 1970 model year car.
*If anyone else wants to trade, I also have a MINT original 1970 style wing that I'd trade for a 71 style in equal condition, I sold the 1970 car mine was destined for and now have a 71 car I'm building.