I have just started the process of renovating my 1924 Marshall and
Rose Angelus pianola.  As this is a first for me, I would appreciate
some information from anyone with experience of these instruments.

To date I have removed the stack from the piano and separated the
primary and secondary valve chests.  Also removed the pouch board
from the secondary valve board.  My first questions are regarding the
secondary valves:

1. The valves are made of wood and the mushroom heads are glued rather
than screwed to the valve stems which makes replacing the vacuum side
leather seat almost impossible without destroying the valve.  Is there
an easy way of doing this?

2. 57 of the valves have a fine coil spring under the head, why not
in all 88 valves?

3. What is the procedure for setting the [secondary] valve clearances,
what should they be?  Most are between 1 mm (0.039") and 1.3 mm
(0.051") travel.

I'm sure there will be other questions as the renovation progresses.
I would appreciate any input.

Michael Rand