Gray on the tip of the fin - Ultracote will easily stretch-n-shrink around the end. Next time leave about 1 1/2" - 2 " of slack (finger hold). Use a trim iron on high or a standard iron at 330 degrees (give or take). Hover the iron just above the film (I mean within a hair) and pull the film down and over the corners first. Then pull and stretch away from the corner toward the center. You can easily overlap the side film by 1/4" with no seams. Your seam will be tight and most importantly fuel proof. Let the film cool and use a new or just sharpened blade to cut as Ultracote's "cutability" turns to crap after it's been heated that much. I usually create a tip "cap" of film - stretch-n-shrunk around all sides of the tip - 1/4" down the sides. Then the side film is just flush cut at the tip - this works great for tips that are basically flat like the SSE.

The wing stripes - since you chose to align the stripes so that the seam between the red and gray is without structure (seam not on the cap strip) you can create a panel of red / gray / red before you apply the film to the wing. Using a big chunk of class, lay out the pieces with 1/4+ seam. Seal the seam (no backing paper on the film) with a low heat trim iron - be light with the touch to avoid wrinkled overlaps. Once the whole seam is "low temp'd" go over the seams with a standard iron on normal heat - 250 - 270. Let the seams cool and the panel will easily pull up off the glass. Then apply the 1-piece covering.

The scrap backing - save the big chunks before you wad them up - great transparent paper - one side is easy to mark with a Sharpie - use to create templates for future covering projects!

pics 1/4 - panels for the bottom and top of my SSE
pics 5/7 - tip of my LT40 fin - I"cut-in"the plane with bits of covering before Ido the fields
pics 8/9 - the finished wing using the panels in 1/4.

HTH