when the wing is slide in place with just the dowels it doesn’t sit in the saddle? if that is the case what it sounds like is you might need to use a piece of dowel smaller than the dowels in the wing wrapped in 80/50 grit sand paper and sand out the holes in the fuse for the dowels. only do a small amount at a time until the wing sits in the saddle. you should put some saddle tape on if you haven’t already, you can get it at any hardware store or your lhs,try to find 1/8 thick single sided tape. that will hold your wing in tight and will protect it from rubbing against the saddle.i have had several wings with the same problem and fixed them in this way.