Confabulous - just to clarify....
RV's are not pop-rivetted together. Rivets are driven in and formed, either with a rivet squeezer or a rivet gun and dolly.
I would caution against making any mods (customisation) as this all needs to be assessed by the PFA and does require serious resource on their part.
And if you do build something - do try and build it as light as you can. I am using 6-32 c/sunk screws on the panelling of my second build as they are lighter than the 8-32 dome heads on my first. Much more work but lighter and more streamlined!
Stik