Nose job
take a wire wheel and clean the area to really see what you have and re post pics.
With the rust on it its hard to tell and you still dont have a clear picture of how bad it is.
If it is real bad I would replace it with a clip from a donor or.....Seriously look into a front clip with a mustang front end. (you have to put in frame connectors anyway). If you are going to do a rear clip buy the whole frame as one piece, You will save a ton of money and a to of man hours.