Anything by Barbara Brundage. Check out Classics on Request (3 volumes). Substantive music for lever harp, close to original scores in sound (and sometimes transcription). Works well on pedal harp, as well.

Do you have much Bernard Andres?

I was thinking of asking the same question. 🙂 it seems a lot of lever harp music is arranged from something else, much of it seems to be made for beginner/intermediate, or for children.

Deborah Henson-Conant also writes music for lever harp. I have her “nightingale” book and it is lovely. I am not familiar with any of her other music but youtube is a great resource.

Is there a certain style or genre of music you are looking for?

William Mahan has a number of theme books for lever harp. The pieces are written as a suite. My favorite is “Colors of Italy.”

Barbara Semman’s “Gentle Spirit” is excellent. There are 8 pieces in that collection.

Andres’ Epices are low to middling intermediate and his Danses d’Automne possibly slightly more advanced and among my current favourites.

I can recommend some more intermediate to advanced original lever harp music. Some of these are from European composers, but they are not hard to find online to order and they are well worth it:
Blue Dream World – suite by Inge Frimout; beautiful music in a high-quality publication (with artwork), and each piece can literally flow into the next and she lists the planned lever changes as you go. It comes with a CD of the entire suite. I love this one!
Laura Zaerr – she writes amazing complex music just for lever harp. “A Living Tradition” is an easier collection compared to her others, like “Dancing with the Stars” and “Wondrous Rivers and Viewpoints”. You sometimes need to write in the lever changes on her music, but it’s worth it and not hard to figure out. For an example of her music, listen to River Right Rhumba.
Kathryn Cater – Grassy Fields is one of her more challenging works. A Walk in the Woods, My Gallery, and all of her animal-themed books are interesting intermediate pieces, with different styles. Don’t be turned away by the kid-friendly covers on her music books!
Performance Solos for the Harp – by Jeannie Chenette. I use her Progressive Solos book with my adult beginners, but the Performance Solos book is at the intermediate level and has great pieces.
Blue Orchid – by Savourna Stevenson; this composer has been writing challenging music for lever harp for quite a while, but is less well known in the US. You can find a few videos on youtube to get an idea of her style. I know Creighton’s Collection carries her music (and some of the other harder to find collections).
Swan LK243 – by Catriona McKay; available as a download on her website (includes both intermediate and a gorgeous advanced version)
Valentia Suite – by Michael O’Sullivan (Fat Rock Ink). I would get the hard copy if you’re buying the whole suite; I particularly like The Coombe Road – Session at Fintan’s (a full video of that piece is on youtube)
Nataliana – by Deborah Henson Conant (Spanish style piece, no lever changes, but it is challenging)
Latin Groove – by John Metras
Easy Swing – by Jakez Francois, includes a ragtime piece!
Phosphorescence – by Alys Howe
Ratatouille – by Clemens Krijger; an unusual book with illustrations; each piece is only a page long, but in a different style and very interesting. It comes with a CD.