The first thing I did was use hot water to pre-bend the ABS binding to be almost perfectly aligned with the body. The idea was to remove most of the resistance that the plastic has and require much less force to hold it against the body as the glue sets.
The second thing I did was more detailed cleaning of the routed binding area, to improve the seam with the sides.
The result - a much better fit. I am happy with how tight the binding hugs the top. The interface between the wood and the binding, on the side, could still be better but I will keep this one and plan to improve as I put additional binding on.
I scraped the binding flush against the top and sanded the side wood to meet the binding.
By the way - the clamp that you see in the picture has nothing to do with the binding. The kit came with one of the sides not completely glued to the neck block. I just glued it back and it's being held tight to dry with a cam clamp.
