hookedonrc,

yes I sanded down the formers just a little where they meet the fuse, I used 1/16" sheeting and you can use scrap 1/16" balsa for your guide for how much to sand down the formers.

note that I glued some thing balsa sticks between formers where the sheeting will meet the fuse side to form a surface to glue the sheeting.

1/16" balsa worked great for me.