Cleaning the keyboard--some photos

Hanging from the music rack assembly--this piece of fabric:

 

It's hard to get a photo that captures the look of this piece of fabric.  It has metallic threads, which leads me to think it must be more recent than the harmonium--but my partner thinks that fabric such as this might have been available in the late 19th-century.  I only bring this up because, as I remove the keys to clean them, amidst the dirt under the keys are strands of metallic thread, which I assume is from this fabric:

A close up of these strands, modeled by Walter:

What was this fabric for?  Since the back of the keyboard is not finished, and since, in the condition I bought the harmonium in, the back of the keyboard is completely visible, and since the one remaining swath of fabric is hanging from the music deck assembly, which floats over the keyboard, I wonder if there was originally an expanse of this metallic fabric that hid the back of the keys from view?  Is this typical of these instruments?  More research needed here.

Meanwhile, here's the back of some of the keys:

There is a spacer surrounding the back pin.  Some of these spacers are glued tightly to the key, although the ones in this photo are all loose, and one is broken.  I'm not sure what their function is.  There is a rail that runs over the back of the keyboard--maybe these spacers keep the rail from settling onto the pins?  In any case, I will repair these if necessary and glue them all back.  Meanwhile, as I remove the keys, each of the loose spacers is going into its own ziplock bag with a label indicating which keys it belongs to:

I'm removing each key and giving it the most gentle cleaning: dusting off the debris, wiping it with a damp cloth, and then storing it in a box.  Note the slot cut into the 10th key from the top: this provides space for the bass forté lever to pass through.

The keys, thus far, have no markings on them at all.  As I remove and clean them, I'm labeling them, in pencil, on their undersides:

 

I finally have removed all the keys from C up through f1, and have exposed the bass forté swell shade.  The lever which opens it (and which passes through the indentation in key #10 as noted above), is clearly visible:

The forward side of the swell shade is leathered; the leather at the treble end is broken and needs to be replaced:

A side view of the keyboard.  Keys C through f1 have been removed; shown here are f#1 and higher.  Note that the keys are carved to provide space underneath them for the movement of the bass and treble forté swell shades.