Just trim it the shape of the stab cutout...
Also if I were you I'd assemble the wholw fuse before gluing anything. just ue rubber bands to hold it together then go back and glue it all.
PS. You think your instructions are killer and you have the updated version. LOL
You can get it to this stage without any glue.
http://www.********.net/caextra27/dcp_0632.jpg