Mine was that exact shade of green. It did not come with Air Conditioning, but an air conditioner was added by the previous owner. The car was wrecked several times, and repaired several times. I traded it for a newer 1980 Mustang in 1982. I still get a thrill when I see one on the road (which I rarely do).
My brother got one just like yours...same color. It had been wrecked but he worked on that thing until I moved out and he moved up to the burgundy one I had driven. Once he fixed it up, I was too afraid to drive it. Way to much power for me.
Eventually, my bro moved on to a truck and my dad sold the Mustang to a stripper (seriously!) and bought himself a little fishing boat with it.