You don't need clamps to glue the pneumatics on the board, but I don't
think you need to collapse the pneumatic before you cover the hinge end
either.  That practice has gotten me into trouble, particularly if the
pneumatics act on the piano action itself.

If you recover the pneumatics and cover the hinge end with it closed the
span will be decreased, and that will cause the pneumatics to hold the
piano action up slightly.  If you try to adjust this out then it won't
have enough travel.

Another place I've gotten into trouble is on primary valve chests.  If
you punch the valves out you will enlarge the hole on the top primary
valve; when it's put back together it will not seat flat.

Something else I don't understand is why some people chisel the
pneumatics off the deck board, and spend hours repairing the damage.  I
always use an old steam iron.  If the boards warp I replace them; most of
the time I replace them anyway.  I can make up a set of pneumatics
quicker than cleaning and hinging the old ones, and I don't have to
worry about warping.

But the most dramatic difference you can make in a player action is to
thin PVC-e or plastic glue and apply it in every internal area that has
suction except the area that a valve will seat, the stack, pumps and wind
motor.  If you rebuild the valves properly it will make a "one footer"
out of your player.  I have to use a solenoid for auto-rewind because the
player action is so tight there is not enough suction to operate a
pneumatic one!

If you want to save some money, use a fan speed control on the suction
motor instead of the wire-wound resistance type.  It works just as well
and is less cumbersome.  I make my own suction boxes and never had to
replace but one -- lightning got it!   Best regards to the group,

Andy Taylor
Sikeston  Mo