I found this piece not too long ago along with the pommel stone for the sword. I have no idea what to do with these pieces. Any advice would be greatly appreciated...

Hold on to them. Then when you get an invitation to visit the dawn star museum go out there. I won't say anything else and spoil it

Sweet...Thanks...Will do so, I have the invitation, the hilt, and the pommel...I am going there...

Expect to get a nice piece of equipment out of it and some nice loot too (after getting a certain key)...

I've done this one so I'm trying to be vague.