Does FSX look first in the plane's panel folder, making it possible to go ahead and not change gauge names ?
I just built a set of test gauges (same gauge name, different functions.) Testing reveals that in both FS9 and FSX, the search path for gauges is:
Main FS Folder (yes, really...); Panel Folder; Gauges Folder.
Gauges in the aircraft's panel folder will be loaded in preference to gauges with the same name in the Gauges folder.
Doug