Wow. That sucks. Here's a few pointers for old Hasegawa kits. Glue the wing tops to the fuselage first to avoid a gap. Then quickly bring up and glue on the lower wing half to set the proper dihedral. Then All you have to do is sand the wing tops to match up with each other. Also, don't use Model Master metalizer, or Model Master Acrylic, or Future. They are all crap and as you found out, don't belong on a model. Also, buy a set of Eduard masks for he canopy, and never ever use old Hasegawa decals! By old I mean anything older than 2000.