I hope this doesnt sound the wrong way but that seems like a lot of messing around. It looks like you did a real nice job of welding the piece in, I would think that your eye and your hand would be enough to tell you how to finish it. Again I dont mean to sound smarta$$ or conceited, its just the only way Ive ever done it....
That rig will never be able to duplicate the profile in 3 dimensions but the flat of your hand can feel differences you cant even measure..it does take some practice tho
my 2 pennies