Roger Waring wants to know what he's in for.  It's been 20+ years since
I tore my Weber D-A grand apart and rebuilt it, but in theory the job
is not too nasty.

Almost everything is connectorized.  The lower key tubing is attached
to connector blocks, maybe 15-20 notes per block.  You unscrew those
from underneath and lower them from the underside of the upper action.

On the left side of the spool box, against the piano case, is another
connector block that carries the expression codes, theme accents, etc.
The hardest part will probably be the hose coming up at an incline from
the rear.  You'll probably have to break it to free it from its flange
in the upper action.  But it sounds like you'd want to replace it
anyway.

You'll also need to remove all the control lever handles.  Then the
whole action should slide right out.

Now, your description may be of a later production that eliminated the
connector blocks and just routed the tubing through the keyboard with
individual nipples.  If so, you'll have to pull off all the bottom
tubing.  At least you'll find out which ones need replacing!

I do know that I've put off working on my *piano* action due to the
magnitude of this task, but for major work it's reasonable.

Mike Knudsen