Start wiping those horn scales down in neetsfoot oil daily and use a q-tip to get the inside of the scales until they won't absorb any more of it. Most likely that will tighten the pins up a bit too. After they are good and oiled, they won't be as brittle and there will be a lesser chance of breaking the scales if you have to repin.
If you do have to repin, as long as you have the scales off, soak them in neetsfoot oil in a zip lock bag for a few days or a week.