I know the wonderful Symphonies of this composer and some of his chamber music so searched IMSLP to see if he wrote any music for organ. The closest I got was this piece for piano but there are other pieces that might transfer well to the organ too.
Franz Adolf Berwald (23 July 1796 – 3 April 1868) was a Swedish Romantic composer. He made his living as an orthopedist and later as the manager of a saw mill and glass factory, and became more appreciated as a composer after his death than he had been in his lifetime.
Symphony No. 1 in G minor (Sinfonie sérieuse) (1842)
Symphony No. 2 in D (Sinfonie capricieuse) (1842)
Symphony No. 3 in C (Sinfonie singulière) (1845)
Symphony No. 4 in E flat (Sinfonie naïve) (1845)