I'm not sure who makes the aircraft models for MS, but they map them in quite strange ways.
I discovered that the 321 engines do things in such a way that you can line up straight lines ok, but try and line up a logo like the freedom sun and forget it. The engine casing and reverser source their textures from different parts of the skin, so one part of the sun was always upside down

Talk about frustrating.
In the end I had to settle for the sun being on the reverser as far forward as I could get it, it was never going to sit across both which is frustrating
