Here's the install of former #4. In the Mick Reeves Hunter, the wing tubes insert into the fuselage and bolt to a small "shelf" on former #4. Here the wing tubes are bolted in as well.
There are plywood plates that glue to the inside of the fuselage at the wing roots that the wing tubes pass through. Gluing these plates in indexes the location of the wing tubes, and thus the wings, in both a vertical and horizontal (longitudinal relative to the fuselage) direction. Thus, the wings need to be on and setup straight before these plates can be glued in place.
The next step is to fit the wings, get them straight, and glue the plates to the side of the fuselage as well as glue the wing tubes into the wings...