The 7/16" from end of dynamo nut to pulley face is quite normal. Still a long way from touching on the outer timing cover, and does not cause any real problem. The spring washer we supply is a thick one at about 1/10", and could be thinner. The base of nut to hex could be reduced by a tenth or so. There is a certain tolerance on the nut of course, and that distance has not been well controlled by the machinist. We might change the drawing to tighten things up. But little to gain from doing so, as this is pretty much a cosmetic issue I feel.