Speaking as a buyer, I would certainly look a lot more favourably on a car with recent service taken care of, A/C working, a roof that's in good shape and nice-looking wheels. The stereo wouldn't be such a big deal so long as you were up front about it - many people like to change that out anyway.
If I were in your shoes... assuming I could afford to, I would have the work done and enjoy the car again for a while before deciding whether to keep it or sell it.
At the very least, you should have it serviced and drive it a bit before you decide. You never know, it might just put a big dumb grin on your face once again.
