As for the canopy seam, I'm guessing you know it's a byproduct of the slide molding process to get the detail on the frame and get the shape right, but yeah, that's super annoying. I had that on my Meng P-51D, and I used the Dallas canopy as a test bed. Sanding it isn't actually too difficult. To preserve the shape, I used the Flex-I-File U-shaped sanding tool that takes a piece of sandpaper on the open ends of the U. That lets it flex so you don't get flat spots. I polished it with micro mesh, and it was like it was never there.
http://store.spruebrothers.com/product_p/flx0123.htm