Steve,
If Im following what you are saying. the bottom bolt only goes through the fuselage skin and stringger. It is a flathead screw therefore the skin/stringer are countersunk to accommodate the head. The 2 bolts that attach the steel bracket are the top 2 bolts only that go through the same piece of angle you are adding to the inside of the fuselage.
I have some pics here. I hope this helps.
http://www.jeffsrv-7a.com/WINGS/05-11-27.htm
This pic kinda show the top to bolts that hold the bracket on the outside and if you look closely you can see the flathead screw at the bottom below the blue fitting in this pic.
In this pic if you look in the part that is circled on the plans you can see the 3 bolts. The top 2 hold the bracket and the bottom one is flush outside.
-Jeff