Rehydrating Dry Preserved Hide

Not sure if this is the right area to post this, I apologize if it's not.
I have a muntjac head mount I suspect is dry preserved. The anatomy on the nose/mouth is god awful and I would really like to try to fix it, even if the improvements are just marginal. Is there a way to rehydrate the hide without it ending up rotting? I've been skimming the forums and have seen a couple posts about rehydrating dry preserve but nothing that really answers my question, just a lot of people arguing over which technique is better. I have experience remounting with tanned hides, but not dry preserve. Is there a special way to go about doing it or can I use the regular rehydration method (salt+water)? I dont plan on rehydrating the whole thing, just the problem areas.

 

Ok, thank you a bunch!