Complex sentence: The church features an organ, built by London organ builder J. C. Bishop in 1839, that was originally in the crypt of St Paul's Cathedral, London, Stephens, p.10 that was probably for a private owner.
Split into simpler sentences: The church features an organ, originally housed in the crypt of St Paul's Cathedral, London. It was built by London organ builder J. C. Bishop in 1839, Stephens, p.10 probably for a private owner.