Hi, I have a question about scribing aircraft rivet details. I've got a number of tools adnd guides for scribing both panel lines and rivet details. (probably more than is good for me! "She Who Must Be Obeyed" constantly asks: 'What do you need that for?') My question is: 'Is there a standard center-to-center distance for rivets on aircraft?? i.e 6", 8", 10", 12"?'