Those are fantastic! What you need is for someone to create a native FSX version via MCX of those are freeware, and assign the materials to blend the environment by the inverse of the diffuse alpha. And also assign some placeholder specular and bump maps. This would allow some awesome bare metal to be done using the lighting engine instead of painting on the reflectuons permanently. Would make your paints look even better. A lot more work but well worth it.
I'm playing with doing my own bare metal right now using the CalClassic C-46 (another old favorite) to experiment with. As for bump maps and specular, I've been fiddling with those a little in my Gee Bee Z doings. Heck, I finally started getting my head around the layers thing a few months ago (since these were done) and have made up my own paint kit for it. It only took me almost 16 years to figure that out! lol