Richard looking good. The little pin hole aren't too bad. I just filled them in with the mig welder(hard with thin metal), or backed them with another piece of steel, if the patch spot waould be covered bu interior trim(much easier) and then body filled them. I like the metal to metal badoy putty for stuff like that. It gets in there rock hard!
That drive shaft looks to be 20feet long! Big truck! Now that you started, just go with it, and do a little each day!