Long Quest Involving Romeo & Juliet

It's the Wedding Jeweler guy in Amoria, who is not called Allegro, but does the job.
He's on the platform above Cody, I think. Find him by the lightbulb over his head.
Bring two silver plates and two diamonds with you, to save time.

Yeah, in MSEA it works. Though i had a really hard time getting those silver ores Getting them was harder than expected.