Your thoughts before shooting primer on my dart

I'm in the process of doing the body work on my dart and thought of something I should probably ask a question about.

The front fenders and hood are off of a car that was base coat clear coated, the rest of the car is factory paint from 1974.
What I was wondering is if I should strip the whole thing or is it okay to sand it down some and shoot primer?

If you want to see my project it's the link below.

Thanks