mrbison;
Too bad about the celluloid rot :(
Whatever you do, don't leave that razor in any closed space and definitely keep it away from your other razors.
Do not put it in a plastic bag. That will only serve to confine the acidic gases from the rotting celluloid and will actually hasten the rusting of the blade.
The best you could do is leave the razor out in the air with the blade open and away from the scales. Better still, unpin the razor and put those scales somewhere else... preferably dispose of them.
- Ignatz