[andyspinstriping]

I'm a bodyman by trade and have done several of these trucks that were in worse condition than that. This one is not too bad, just take your time and measure everything out! While the cab is still anchored to the frame weld in some bracing so it maintains it's shape. X-bracing side to side through the cab and then in the door opening should work good. Once its braced you can take the cab off without worry. With how far gone the metal is you might have a hard time doing the braces first and then moving to the floors and the rockers...you might have to take awhile and get some exacting measurments and then go in reverse starting with the rockers then the floor then the braces. This is because the braces weld to the floor and the rockers and yours seem to be pretty much none existent. Another tip that will help you out tons is after removing your rusty metal and before welding new pieces in try to get everything sand blasted. This will give you clean metal to weld to which is important for structural integrity. Get some weld through zinc primer and coat everything good before welding and you should get a quality repair...I will be doing all the same panels in a 61 Apache starting in a couple weeks so I will post pics of the process and you can follow along.
Good luck!