My story for what it's worth.....
Yeah, it's true, I had to remove all the gauge files too to make it work in FSX on my XP operating system.

However, later, when I installed Vista 64 and reloaded FSX and reinstalled the 707 without gauges, I discovered FSX was unstable, with missing textures on the 707.

After much testing, I discovered the solution (for me anyways) was to disable user access control (UAC).