I have restored several of these players.  Yes even at this age, the
players need almost as much as the ones from the 20's.  The plastic
valve blocks will pop off, but it takes work to do so.  They will also
pop open with the use of a razor blade or rather the blade out of a
Stanley sheetrock knife laid along the crack on right and left sides.

I find the reason these Aeolian players played so abysmally and played
every volume of loud there was, is the simple fact that most of them
had valves regulated to give 80 to 100 thousandths in travel.  A mere
.035" will do so much for playing soft.  The sponge neoprene is also
short lived.  The surface of this substance became rough and leaky
within months of first installation.

I use leather with cardboard centers and sand down the top plastic
piece until the travel is correct or you can shim the valve under the
leather.  PVC-E glue or Tacky glue will put them back together.  Sand
them 'til the open end is smooth for gluing to the old decks after
they, too, are sanded.

There is a good member of this group now who makes these plastic valve
blocks.  His are far superior to the originals.  They are priced okay
to replace the whole set with new.  I have not found any reason to need
to build new decks as the old ones work very well.  The pneumatics will
most likely need recovering and while they are off you can belt sand
the surface where the new plastic valve blocks will be glued.

These actions are simply not the problem to rebuild that so many fear
they would be.

D.L. Bullock    St. Louis
www.thepianoworld.com