I think it's real and I believe it's Cohen-1, according to: http://www.coinfacts.com/half_cents/1803_half_cents/1803_half_cent_c01.htm
Could those nicks be consistent with some sort of holder or fob? They aren't evenly spaced, it just look to clean of cuts. Looks real tho to me. I have an 1807 in about the same condition.
If they were from some kind of holder I would expect them to be evenly spaced. It looks to me like it was "attacked" by a pair of scissors or wire cutters long ago and then continued to circulate.
That to me would explain the better rev. As the obv. Shows a heck of wear. Looks like a genuine half cent to me.
You wonder what possessed someone to do that (cut up the edges). I guess there wasn't too much entertainment in the early 1800s.
I would think a watch fob. As take half cent was still a lot of money in those days. As to buying power. But if you old not afford gold a chain with a coin on it was better than nothing.
so many early half and large cents survive with all sorts of damage. This one is real and has a nice look over all.