This took way too long. These crossties are essential to the squareness of the overall forward fuselage, and I was having a lot of trouble getting a satisfactory fit on the upper tie. I had to do a lot of reshaping with the Scotch-Brite wheel, and playing around with the fuselage sides to keep everything square and get a decent alingment on both sides.
In the end the fit is pretty good, but there's a little more gap on the sides that I wish was there. I don't think it's a structural issue, but I would like a tighter fit. Oh well.