[1] Notable initially for pleasing small church and barrel organs, Walker achieved a breakthrough with the order for a large three-manual instrument at Romsey Abbey, Hampshire in 1858, including a thirty-two foot Pedal Open Wood.

Arguably, the heyday of the company occurred towards the end of the nineteenth century under the leadership of James John Walker (1846–1922), the youngest and only surviving son of Joseph William.

The company developed a reputation in the 1890s for excellence in massive diapason voicing using scales and pressures for flue work greater than those used by Hill or Willis.

Walker also later rebuilt the Gray & Davison concert organ at the Crystal Palace, increasing its power to carry across the vast space of the central transept.

After James Walker's death, the reputation of the firm in the "first division" of British organ building lasted through the Second World War.

Today, the business has four distinct parts under the umbrella of "The Walker Group": restoration work operating from premises in the Wiltshire town of Devizes; tuning, supplies to the trade and a small new-organbuilding practice in Brandon.