I guess I am a little confused, where are you going to use elevator bolts? They are not needed at the gas tank cover to fender joint. Align the gas tank cover and fender and hold it in place with vise grips or a "C" clamp. Drill four 5/16" holes through both the fender flange and the gas tank cover flange and secure with bolts and self locking nuts, do not over tighten.
If you’re planning on using elevator bolts at the top of the gas tank cover IMHO they are not needed and you run the risk of making the cover not fit properly by adding the extra material for the elevator bolts.
I went through this very same thing on my 34 whether or not to put bolts in the top edge of the gas tank cover. The general consensus is they are not needed and mine have been that way going on seven years now with zero problems.