Auto body repair & detailing: 1967 Mustang rusted unibody, collision expert, perplexing problem

Question
Hello Ken. I'm a fellow body tech with a perplexing problem. I am helping a buddy redo a rustang, and the s.o.b has SEVERE cancer in the floor pans, front torque boxes, and the unibody rails from the cowl back to the driver seats. 1 rocker is solid as a rock inside and out, 1 is rotted pretty badly on the outside. It goes without saying that the quarters and outter wheel houses are junk, also. I think we should start by replacing the rusted out rocker before doing anything, to give the car some strength in the floor. Then I was thinking we should move on to the torque boxes and unibody rails, followed by whatever the rear torque boxes need, then the floor pans. After that, I figured on tackling the rear frame rails behind the axle, followed by quarter replacement. What say you? I'm a collision expert, I hate rust with a passion. I've never worked on a car with this extensive of rust, and  don't want to tweak the car and have panel allignment problems from hell. I really need another opinion. Thanks, Bill  

Answer
I believe your right in line. Just Do Not Take Out To Much At One Time!!. Also let your friend know what he is in for $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$.
I hate rust work to and do not envy you good luck my friend. My boss just did one a 65 fast back same deal $10,000 and still not enough for me.
                Thank you for the question!
                Ken