Most interesting!....I lived in Ealing until the late 1960's and well remember playing this organ in the 50's ...unfortunately I was then rather a "rev up the large motorbike/organ " youngster and well remember the elderly verger there telling me "there is no need to make a meal of it" ..meaning the probably foul racket I made !
Pity to have played it then and not now as I would now be exceedingly interested to see how French- influenced it was.
I do,though clearly remember the extraordinary piston arrangements!
A propos of Gern/C-C I do remember that,in the early 50's, when Mander inspected the(somewhat derelict) instrument in St Barnabas Ealing, in his report he mentioned that some of the pipework looked to be by Gern. There was a rather beautiful floating quality of the C-C sort to the Open Diapason on the swell,and this might have been the pipes he mentioned? Perhaps G's French pipework escaped into the general environment?
Cheers Richard Whitaker