I'm 72 years young. I have a friend who is 82 and we are both hard core do it yourselfers. Here is what we have learned. You always do your learning on the actual project. You never get to do your learning somewhere else and then come to your project filled with knowledge. Fortunately there is some amount of bleed over of knowledge but we both do a never ending assortment of projects so we are both constantly in the learning curve. It beats sitting in front of the boob tube and slowly dying though.
Wally you do nice work . after 72 the frames are wider so if you are using a newer frame you may want to test fit the body on the frame because you may have to cut away the inside cab corner to fit the body on