Thanks for the suggestion Mike.
Those old cardboard coffin boxes, especially the ones for heavier razors, deteriorate at the ends. Probably from the razors being put away damp or sliding in the box and banging on the ends. I have a few in that condition.
I was scanning my local Yellow Pages and discovered a book binder who also does restoration work. Think I’ll take them in to him and see if he has any ideas. Seems like it might be similar to what he does for old books. If it is too costly, I’ll try the fabric idea.