Here are my Shimano Dura Ace 7400 brake hoods, they are in that no-man's land, still a little flexible, a crack in one but small, and not yet hard as a rock or turning into brake hood goo. They are really hard to find replacements for, nearing unobtainium status?, so are there any products that could restore some of the flexibility, preserve what I have left in them?

My thanks.