When I bought my '70 Duster, the body looked good, but the underpinnings were neglected. In my case, I did start from the rear and worked to the front. Rear brakes were ruined & useless by fluid contamination from rear axle fluid. As mentioned, get the important things done first, like brake inspection, steering, and the like. Build the car the way you want as you are replacing parts. My rear springs were bad, so I opted to get better ones with a little more lift. Lots of folks go for the appearance of a car with little attention to the important things. Have fun, sounds like a great project!