If this has been said once it should be said....
Over and over again.
If you have razors that are rarely used and are being stored even if you have them "well protected" inspect them on a regular basis. I usually do a few times a year and yesterday I was doing my usual inspection and to my horror found the celluloid scales on my Bresnick Gold Mandarin starting to deteriorate. Yep, there was this maybe 10mm, thick red splotch on the neck of the razor. I was able to clean it off with Simichrome but it wasn't easy. Luckily no real damage done to the razor but the scales are toast and that razor has really unique celluloid scales. The razor was really well coated with oil and the rust formed anyway probably from the chemicals given off by the celluloid. I've seen this before so have to conclude gassing celluloid will trump normal protection methods.
So once again the moral of the story is check your razors often. (by the way there is a picture of that razor in the razor clubs-daffy ducks)