Hi, Nick. Seems like no one is anxious to give you the bad news so I'll be the "bad guy" this time. This is a job for a pro! Many chemicals that work great on most surfaces fail miserably on leather. They "dry" out the oils that are in leather and make it succeptible to cracking. Assuming that you, or someone, paid $300 or more for the jacket, $50-100 to get it fixed right is still a deal. Remember that you aren't just paying for the labor. That's the easy part usually. You are paying for the knowledge, experience and assumption of risk to get the job done right. Most cities have one or several shops that do this specialized work. First, look in the phone book to see the potentials. Then visit every dry cleaner and ask them who does their work. They might not tell you and want to send it in themselves. Don't let them unless you get this from whoever does your dry cleaning now. Tell them up front that the jacket is "dear" enough to you that you will start a small claims suit if they mess it up. They probably will not want the risk of loss of your business and the suit, so they will give you the info.
When you have narrowed the choices down to a couple, take the jacket to the pros directly. If you can do it easily, show them the "before" pictures you have taken. Give them all the details that you can about the problem and get their quote. Don't bother asking how they will do the job. They just might leave out some important details or have some other "lapse of memory" that you can't hold them to. Then make a decision on who will do the work, let them do it and pray. Be prepared to tip big or carry out your threat to sue. Sorry, but that's the best way.