I spent a lot of time laying out where these brackets were going to sit. They need to be in the same place on both sides. I double checked by having the sides together and going over all the measurements on each side several times. Then used 5 minute epoxy to glue the parts in the correct place. The holes were used as a guide along with an egg cup drill bush holder to keep the drill straight.
The next day I dremelled out the reverse side down to the timber longerons to allow room for securing the bolts with a socket. These are later filled with foam and micro.
