Gold jewelry would likely work the best. Something that looks older, as if it were gotten as an inheritance after a loved one passed, though really the shape it takes isn't that terribly important as long as it is convincing enough to be sold.

[He paused at that. Ambassador himself, hm? Dio could see the uses of such a position. The power and influence, as well as the connections it would come with.]

I could certainly throw my hat into the political ring. It would be a quite profitable venture for the both of us, I believe.