I hope this won’t count as cheating since I would be 93 before I’d ever be able to play it, but the c# minor Impromptu by Reinhold that Basel Sara has been posting about on another thread sure would be a nifty encore piece, and it sounds as though it would be great fun to play.
I think we’ve pretty much settled on the fact that it was written for piano, but to my ear, it sounds better on harp than it would on piano, and here’s the best part, you can download it and print it free. The copywrite on the music appears to be 1896 or’98, so anyone who wants it can take it legally.
I posted the URL in the Professional Harpists voume. Give it a look and see what you think!