Lady Dagger advice: fix it(how?) or leave it alone?

[Legendary_Jarl]

Thank you very much to all of you for your responses. Since I don't have much experience and I don't want this piece of history to be ruined I will not attempt any major repairs. That being said, I spoke with an antique arms dealer that told me of a trick he uses in this situation involving black string and it worked well. You can hardly see it and the guard doesn't rattle anymore.