Congrats on your warrier ram! It's really up to you. You may want to wait a while and how you feel with it cleaned up how it its.If every time you look at the euro mount you cringe, I'd get it fixed. If you are excited every time you look at it I'd pass on getting it fixed. Put the skull up where you see it every day before making a final decision that makes you happy. It doesn't really matter if you wait. If you get it fixed you are stuck.
In regard to repairing the horn. There likely aren't that many experienced taxidermists that I would trust a project like that. Sculpting and painting to match is a major art in itself! The last thing you likely want is an ugly repair job that you aren't proud of! My guess is that most taxidermists wouldn't have a clue and some may have more experience than others.
I use apoxi-sculpt all the time for repairing horns and broken tines. I repaired a gigantic elk antler shed once that had 3/4 of the burr and base missing. It turned out amazing. Apoxie-sculpt is pretty remarkable stuff. Next to the sculpting, matching color is one of the toughest parts. It may take a gob of color layers to match things correctly. It's really nice having a reference on the unbroken side.
I have lots of experience repairing horns and antlers. If I had a whopper auodad I would likely fix it just because it would be a challenge that I'm pretty darn good at! I think the broken area doesn't quite show the full potential of what that critter was like prior to be broken. Although he is awesome, the broken side is a distraction, and he may not look nearly as impressive with the broken side? I can also see the point of showing off what a warrior he was and leaving him as-is. It's really a judgement call and what makes you happy.
Take your time, get him cleaned up, and put him in a place where you can enjoy looking at him. If the broken side still bothers you....get him fixed!
