Thanks guys. The attachment points at the floats have been smoothed out and rescribed as good as they will get. Access, especially to the inner surfaces is extremely limited so the imperfections that still exist will need to be left as is.
The large square holes that remain are for the additional braces that run from the floats up to the middle of the wings. These were detachable so that the wings could be folded. I was hoping that I could use these additional braces to help align the floats which, as they currently sit, are very slightly off center. Unfortunately, once again the fit of these braces was not great and using them to pull floats into alignment would have made the brace fit even worse. As it was, I could barley get one end to fit into its hole so I decided to live with the slight misalignment.
The next step was to ad the wire bracing and I decided to start with the horizontal wires between the floats. To do this, I drilled some holes in the gusset plates that attach the lower braces on all 4 corners:
Next I threaded a length of 6 lb nylon fishing line loosely through the holes and secured one end with some thin CA.
The opposite end was then pulled tight and another dab of CA held the line in position. The excess was then cut off and the operation was repeated on the other side. The wire bracing was finished off by adding a small square but of styrene card at the intersection point.
That finishes off the easier one. The next wires run parallel to the floats so access and the ability to pull the lines tight will be a challenge.