How attach sheet metal to 4130 tubing?

[jwzumwalt]

I am converting a single place Stit's Playboy to two seats.
I stripped the fuselage and am repainting it.
Rather than use fabric, I would like to aluminum skin it;
and while I am at it, put a little curve in the fuselage profile.

How can I attach curved forms to the square fuselage without
penetrating the tubing. I do not want to use blind rivets, bolts,
or screws because I would like to linseed oil the inside tubing.

I could make slots in the forms and create some type of
aluminum strip clamp around the tubing but I wanted to check
with the group and see if someone else has used, or know of a
better mouse trap

There are already one or two pieces on the belly that was safety
wired, but that looks like it quickly compromised the paint and rusted.

FYI - I would create new forms with a flat edge against the tubing.

Thanks for the suggestions!