gorrilla glue or titebond III would work to glue the two pieces together but how do you intend to attach the rope lip? If you are not going to sew it, then you will need to use epoxy and you might as well epoxy the hoops together as well. I wonder if its possible to use another wooden hoop (cut down to 1/2inch) as the lip. You will need to make it about 1/2 thick (1/2 inch x1/2 lip) to work and need to fill in the gaps with more hoop, but I wonder if it would work. (the gaps would come from the increasing diameter of layering the hoops) Personally I like bigger coamings, so I will never find out.
Scott