AT the time of his brother's death in 1796, William Gray was around forty years old. He now became sole proprietor of the business. It was William's energy and business acumen that was to transform the workshop, over the next twenty years, into one of the most productive and profitable in the metropolis. He also had what can only be described as luck: the death of the King's organbuilder, Samuel Green, just two months after Robert Gray left a gap in the market, and while Gray picked up little of Green's cathedral trade (most of which went to G.P. England or John Avery), he undoubtedly benefited in other ways.

Probably he felt a responsibility for the welfare of Robert's orphaned children. He was, in any case, one of their trustees, and it was arranged that they should remain in the family home. Any responsibility for Margaret ceased when she married Hugh Atkins Reid at St Pancras (Old Church) on 1 June 1799, but Anne Marie was still a minor, aged twenty, and Benjamin was only fourteen years of age in 1796.

By this time, William Gray had a family of his own. On 19 April 1789, he had married Mary Dew at St Mary’s, Stoke Newington, by Archbishop's Licence. The two witnesses were ‘Ann Barbut’ (probably a member of the Barbot family – Gray's neighbours in Quickset Row) and ‘James Boult’ who, many years later, was named as an executor of William's will, in which he is described as ‘of the Consol Office Bank of England Gentleman’. Mary was the widow of William Dew, a cabinet-maker and upholsterer of Great Pulteney Street, Golden Square, in the parish of St James Piccadilly. He was in all likelihood a widower who had married as his second wife a younger woman; Mary Gray (as she later became) died at the age of seventy-nine in 1842, so she was probably born in 1762 or 1763.

Three children of William and Mary Gray are known. John, the eldest, who worked with and eventually succeeded his father, was born on 24 July 1790; his baptism took place at the Percy Chapel in Charlotte Street on 22 August.