experimenting with xanita

My design relies highly on ribs slotting in to an outer 'loop' or 'skin'.

Here's an experiment where i've made a slot for a rib to fit into a curved section:

I though the stripped section on the curve looked a bit weak so here is an alternative method:

I also thought i'd see how tight a blind tabbing system could be:

This tab fit rather tight and i think it would be a good joining method.