Bryan, I have just last night built the bottom end of my 750 S project, so the subject of crankshafts is fresh in my mind.
I would be more concerned with the condition of the threads and the end of the shaft on the timing side. Make sure that the very end is not deformed, mushroomed or peened over as this goes through an oil seal into the timing cover and is where the crank shaft oil-feed comes from. I'm sure you already know this so appologies if I am being too pedantic.
I have just looked at a crank for one of my other projects in the workshop and it occurs to me that in the absence of V-blocks if you simply rolled the crank supporting the shafts on two parrallel pieces of wood, alloy or anything else straight you would be aware if there was any discernable bend, in the same way that one can roll push-rod tubes on a glass surface to check for bends. The Norvil bottom end kit seems to have everything you will need. If you already have superblends fitted you can slightly grind the inside of the inner journal on the old bearing and use it as an easy removable inner for setting the end float on the crank. The shims are meant to be behind the bearing inner on the timing side(most parts books diagrams are incorrect in this) and it is very difficult to remove the new inner to add or remove shims once it is pressed onto the shaft, so this inner bearing race once modified can serve you well for any future Norton rebuilds.