Off the top of my head (as I'm on the road and away from my office for the next two weeks):
Geoffrey studied composition with Edmund Rubbra at Oxford. He was lecturer in music at La Sainte Union teacher training college (long since closed down) in the 1960s-1980s, where the music number one at the time was George Self.
He had a Mass setting (don't remember the title) published by Kevin Mayhew or Geoffrey Chapman (don't remember which), and then put together A Responsorial Psalm Book, the first properly published collection covering Sundays and major feasts of the complete three-year cycle, containing settings by a large number of composers, both existing settings and ones he newly commissioned for the book. This went through several reprints, then fell out of print. The publishers were persuaded to do one more printing, which turned out to be the last. Although sales were steady, they were not fast enough for the publisher's bean-counters.
In the late 1970s Geoffrey founded his own one-man imprint, Portsmouth Publications, which issued other mass settings of his, a setting of the Exsultet, and other works. Another one-man imprint, Magnificat Music, published Geoffrey's Psalm 65 ("Shout all the world", a Michael Hodgetts text), included as a supplement to the first issue of the Society's journal Music and Liturgy in 1974 after the Church Music Association had rejoined it.
Geoffrey then edited Music for the Mass (the "red book"), a collection of much existing music from the one-man imprints, which effectively terminated the existence of many of them. This was followed by a second volume (the "green book") several years later.
For many years Geoffrey had run liturgy and music courses in the diocese of Portsmouth in collaboration with Dom Romuald Simpson of Douai Abbey and Fr (now Canon) Alan Griffiths. In retirement, Geoffrey became volunteer director of music for the diocese of Portsmouth. When the diocese set up a new paid position of Diocesan Director of Music combined with Cathedral Director of Music, Geoffrey continued to assist in the new set-up.
By then, though, he had developed cancer, and his wife Marian was eventually discovered to have terminal cancer herself and rapidly predeceased him. Shortly before his own death, he was visited by Bishop Crispian Hollis, who pinned a Knight of St Gregory medal to his pyjamas in recognition of all his achievements for Catholic church music not just in Portsmouth but nationally.