I have just picked up a booklet on the organ at St Swithun's, East Grinstead. This is a remarkably good instrument which works very well for a major parish church made by Morgan and Smith in 1937.
Harmonics are very much in fashion, with a whole division of them crowning a new instrument currently receiving a lot of attention on this forum and others . . . but the period of the 1930s is interesting. Harmonics, with the Cornet, are not new to organ building and were the organ builders' way of getting around the Papal edict that double reeds were the work of the devil, thus prohibiting imitations of the Hautbois. But in the 1930s fourier synthesis had come to the fore with the Hammond organ, based on addition together of pseudo-harmonics to create tone colour.
Wurlitzer would often make synthetic stops from ranks of pipes then and at East Grinstead, the synthetic Solo division did the same:
Clarinet: Flauto Traverso, Nazard and Tierce
Orchestral Oboe: Viole d'Orchestre, Dulciana, Nazard and Tierce
Cor Anglais: Viole d'Orchestre, Wald Flute, Nazard and Tierce
Vox Humana: Dulciana, Vox Angelica, Nazard and Tierce
I have not had the opportunity to try these - has anyone come across examples elsewhere?