Hi Dennis.
Prior to restoring my '36 Chevy high cab pickup (same body as your '35) in the early 1970s I was a VCCA member and had heard numerous horror stories about ill-fitting wood kits. The kit sellers' excuse was always something like "There was a lot of variation in those old body parts so a lot of custom fitting is necessary in using the kits". Because of that I made my own wood using the old rotted wood pieces as patterns. Now, 40+ years after completing the restoration the home made wood is all still holding up well.
So that project is definitely not beyond the reach of a motivated amateur. You can do it!