Here I am fitting bolts to the upper box section as well.
To get the nuts on the inside of the box sections Spencer had a fantastic idea to use a short length of pipe , to which he attached a ring spanner. We then used blu tack to hold the nuts in the spanner and pushed it into the box section to meet up with the bolt.
I held the pipe while Spencer used the allen drive in the rachet to tighten it all up. Teamwork!!!