The comment regarding highest stresses, I take it that would be bending rather than axial stress? Reason I mention this is because the axial stress is highest at the root as would be bending stress to think about it ( depending on varition of CSA) so not sure where you get this heuristic 3-4 inches!
Dont know anything about the practical side of prop repair, but coming form a stress analyst background on turbine blading, thought it would be an important addition.