I ended up dismantling the entire car and rebuilding everything. The car was sand blasted except for outside sheet metal which was hand stripped, all minor dings fixed and any rust, surface or otherwise repaired. The underside, front K frame and steering, rear axle inside the cabin, under the hood area and trunk sprayed with Por 15 rust protection. Then sprayed with Por-15 finish coat chassis black, Areas to be painted with finish coat were then primed with Por-15 special primer. The car was then primed with 2 part primer before painting. Obviously this is the abbreviated version as anyone who has done this knows there is a lot of sanding, fitting, block sanding etc.

Attaching a picture of underneath the car before applying the chassis coat semi-luster black finish.