This is cambridgeorganists.org Designed and produced by Stephen Taylor for the Cambridge & District Organists’ Association
(at the back).
Note the pierced slides and tuning handles. A lot of effort for a rank that, contrary to what the name suggests, sounds just like a Dulciana.
No.2 : Pipe Metal
Spotted Metal is an alloy of lead and tin with the tin component being between 45 & 55% Proportions in pipe metal as a whole vary between 15% and 100% tin. There are also small amounts of antimony (which was used in type metal to give hardness), bismuth and copper. When the organ in the Buckingham Palace Ballroom was restored, pipes damaged beyond repair were made of metal specially cast by Laukhuff to precisely match the metal of remaining pipes in the ranks. Lead and tin have different solidifying temperatures with mixtures in between.The appearance of spotted metal is caused by visible crystals formed as the metals cool when in roughly equal quantities. www.chemguide.co.uk/physical/phaseeqia/snpb.html
No.3: Funny Resonators
Over the years, pipe makers have developed a great variety of resonator shapes for reed pipes, particularly the fractional length resonators on the Vox Humana type of stop.
Here is the Apfelregal:
Stops & Pipes Page 1
No.1 : The Keraulophone
Some others illustrated in Audsley