William Hayes (1708-1777) was for most of his career organist of the university church at Oxford, and known as a follower of Handel. This concerto can be found in the Novello English Organ Music series, and the slow movement in particular is a bit of a gem.
Played here on the Brasov organ in Silbermann temperament which seems about right for the music.
In the Andante the registration is:
Bass - Unterwerk 8'
Tutti - Hauptwerk Viola da Gamba
Solo - Oberwerk Hohlflote 8', Quintaton 8', Rohrflote 4'