As I recall, these were about 1/4" wide strips with one edge rounded "out" and the other rounded "in." Looked sort of like a worn hardcover book, where the binding rounded out and the page edges rounded in. Kinda )_______).

They might be useful on a straight, cylindrical fuselage, but when you have to taper them to follow more usual fuse forms, it just makes more work. Two tricks to taper square-edge planking strips to fit:

Sand (or cut, if you're that good) the cross section to a slight wedge, - \___/ (exaggerated) - like barrel staves, so there's a close fit to dress the next piece into.

Keep the strip longer toward the wide end of the space. If you thin the width too much in places, you can slide it towards the thin end and try to do better.

It isn't as hard as it might sound, and without the 'outie' and 'innie' curves fighting you, you can get full depth pieces - down to the formers all the way around, with minimal 'lapstraking' as on small boat construction. Sanding needs less filling, but it will need some.

A strong and quite light way to build a curved and tapered fuselage. Good work in those pix of a fuse!