Since you have a bunch of good suggestions for how to handle the "small space between the wing saddle/wing.", let's address the "small amount of play at the dowel/dowelhole".

Easiest way to handle this is - if you can get to the compartment in front of the wing dowel hole (such as the tank compartment) - put a small square of lite ply over the hole with the correct diameter hole in it and glue this to the front of the former that has the dowel hole. Drill the hole in the small square first, have the wing on the fuse with it sitting correctly, place the square over the protruding dowel end and then glue the square to the former.

Alternatively, with a square of ply (approx. 1"x1"), use it as a template to cut the existing former part with the hole in it, glue the new piece - that doesn't have a hole yet - in place and then line up and drill the dowel hole as was originally done.