Mike has a number of works available from the Lulu print on demand site:

Child of Pure Harmony: a sourcebook for the single-Action Harp

A very imperfect instrument
A practical approach to playing the historical single-action harp

Approaching the Triple Harp
a ‘how to’ book for harpists moving onto the chromatic instrument

6 Georgian country dances set as very easy duets. Ideal introduction to duet playing, or for more experienced players to expand from.

Mazzinghi Sonata No 1 for harp/pianoforte, and flute/violin.  3 movement sonata c. 1803

Photocopyable violin part integral to the harp part, but a separate part available here

The Fountain Plays

A short piece of pedal harp, in the style of the 19th C ‘fountain’ pieces. Written to commemorate the restoration of a  19th C Pullham co. fountain on the Isle of Wight.

The Wolf in the snow
An easy, diatonic piece for almost any type of harp; atmospheric, rather than demanding.

Le Cygne

An arrangement for pedal harp by student, and friend, of Saint Saëns, Clemence de Grandvale. Lyrical, and approachable.

Georgian Miniatures.
A selection of 12 short pieces for single-action pedal harp, but equally worth playing on the modern instrument. Some will work on lever harp with little, or no alteration.

Late Georgian Country Dances, for harp, or pianoforte.
12 dances, with steps, as originally presented in period sources, and dating from between 1810, and c. 1816.

Lorenz Sonata no.1 for hook harp and violin:
Written for the hook harp, this duo sonata works equally well on pedal, or lever harp.

Sonatina in C:
A short, easy work designed to introduce early stages students to the concept of the sonata.  Only one movement requires a chromatic shift, the others can be pre-set at the beginning of the movement. Accessible, and pretty, it makes a useful exercise, but is also worthy of performance.

Andante con Varazione by J E Weippert.
No chromatic shifts requited once the key is set, so playable on pedal, or lever harp

Mike also has a number of works available  with Creighton’s collection