Thanks, compared to some on this site my amature status is pretty clear but I am pretty happy with how the project is going so far. Although the whole project has been on hold for a few months while I work on a different project truck (1997 Chevy 1500) for my grandson.
Generally I cut out large sections that included the rusted areas. In retrospec I probably should have gone further in some areas. I bought patch panels such as floor pan pieces that went back almost to the seat area but cut them off to match the cut out floor area, similar process with the inner and outer cowl panels. The inner to outer cowl panels were the short versions. I was lucky in that my rocker panels from the door hinge post back and my door hinge posts were in good condition. My seat riser had been removed by a previous owner but I was planning on updated seats anyway so that wasn't a big problem. I have done selected area cut outs and patch installations on the fenders, box sides, and replaced the rear stake pockets to resolve rusted out rear box cross member and hinge mounting areas.
The body work support on this forum is great. I am sure if you post pictures of what you have you will get a lot of advice (sometimes conflicting) about how best to proceed.