Yes, it does appear to be a case of cell rot and if so, you should get the scales off that razor as soon as possible. That is a very nice blade and probably can be saved.

Those are some nice looking scales, unfortunately that style of faux tortoise is notorious for off gassing. Something in the chemical composition of how they were produced and more importantly stored causes the off gassing. Heat and stored in an enclosed space seem to be triggers, like a glass display case in direct sunlight.

You can slowly close the blade in the scales and see if the rust pattern on the blade matches the light and dark blotches on the scales, on both sides when fully closed. If the rust patterns and blotches match, that is pretty definitive. As said judging from these photos and without having the razor in hand, it does appear to be a real possibility.

It is very common on light colored “Ivory Imitation, Cracked Ice and Faux Tortoise from the turn of the century. It is one of the first things I look for when I see that style of scale on old razors. I saw some today at an antique show.

If so, get them off quick and save the blade. Do not store those scales with any other razors.