My '72 is put together the same way.
Blue painted pop rivets for the belt line trim.
I was also surprised that the banana wraps were allied on top of the shell. I've put a thin bead of sealer where the pieces meet.
One thing I did not like, and am in the process of changing, is that the trim strips over the wheel wells were pop riveted to the plastic wheel well liner and have all pulled loose.
I'm using a backing strip of 1/16th inch aluminum to sandwich the plastic between the metal in an attempt to stiffen the sidewall and prevent the liner from tearing out anymore than it already has.
AirForums # 2806
WBCCI / VAC # 6411
Not All Who Wander Are Lost.
Avid supporter of trailing edge technology.