I am also restoring a 1948 Dodge truck. My project has been parked in my garage for 25 years, waiting for me to have time and money to come together. This is finally the year. I live in Southeast Alaska where it rains over 150 inches every year and we're right on the coast, making rust a real problem. Most of the body panels and cab are not painted on the inside and underside. I'm doing a combination mechanical repairs and rustoration, fortunately mine has a remanufactured engine and it runs. The brakes were toast, so I rebuilt with new. I also converted the front brakes to disc breaks and new master cylinder.
I have torn it down to the frame and drive train. What's left is the stripped down cab and now I'm ready roll it back on the frame so I can get to the underside and frame underneath. I have been repairing the body panels one at a time to fix the rust and damage , a lot of welding. I only have a oxyacetylene torch for cutting and welding and a whole collection of hammers and grinders. I'm about half done with the metal work.
Good luck with yours