I have recovered a British Aeolian action which had retaining straps
on its main sprung reservoir to stop it opening fully.  The straps were
put on first, inside the main cloth.  They really stretched when the
springs were put in; the reservoirs had no access hatch to allow the
springs to go in later.

Aeolian actions typically have stop rails to prevent pneumatics hanging
fully open, and also to prevent them fully closing.  I am sure Art
Reblitz comments on it in his player piano rebuilding book.  He says
it may well be the reason for the longevity of these actions, as well
as the good materials used.

I have come across a Standard action where the reservoir coil spring
snagged against the cloth and had punched a neat hole in it.  Whether
this was a one-off mistake in spring placement or cloth dimensions
I don't know.

Julian Dyer