Im no expert but on my Sig SE they used a pre-drilled dowl. The fin and stab were drilled out to accept the dowl. Glue the dowl in the holes then you make the braces using a solder clevis on one side and a regular threaded clevis. Then all you do is put a screw through the clevis into the pre-drilled dowel and on the other side connect the other brace and put a nut on the end.. Do the same thing on the bottom except they used a blind nut mounted on the inside of the fuse. You bring the two bottom braces together and they are attached in the same hole at the bottom of the fuse..

Joe