You can't drive any sort of performance car or V-8 car until a certain age? Wow, I'd never heard of that before.
I've been driving V8s since I was 14... but they've all been excessively slow land yachts. I'm pretty sure there's plenty of family sedans that could have easily dusted my 360 powered Chrysler wagon.
To the car at hand- it looks pretty saveable, I'd go after it. It'd be a good learning experience and probably a lot of fun and frustration, but as long as you stick to one project at a time, you'll be alright.
It sure beats the living daylights out of my free 280ZX... haha