I don't know the Tilden Park Organ.  Smaller Gasparini organs (52-key
size) often had no pipes under the bottom and even no flue bass at all!
The bass was entirely played by a set of lingual "bombardons", with a
very pleasing military band effect.  If you could send me a picture I
could tell more.

Hans van Oost,
General Secretary, KDV
Naaldwijkseweg 262
2691 PW  's-Gravenzande
NETHERLANDS
tel: 0174-414538