I trust that when you have restored 100 more pianos things will make
a lot more sense to you.  I agree that a piano with ALL that stuff
missing would be one I would have trashed for parts as well.  It
sounded to us that you had taken 3 or 4 borderline chicken coop pianos
and had merged them into one which would be wasteful if they had all
their parts.

For future use, and not for this poor piano, I will give you my take on
some of the problems you consider major.  I also consider them major,
but not insurmountable.  I also must do things in ways to save money
when possible.

> The pinblock has only three layers (cheap) but there is a block of
> wood glued to the back of that which the back ends of the pins reach.
> The whole affair is 2 1/4" thick.

Yes it looks like that, but actually the pin block is only about 1.5"
thick and the rest is support and spacer.  Probably the top three
layers are of wood.  Many piano companies used 2,3,4 layer pin blocks
and they were as good a piano as any other out there.  Go back far
enough and they used a solid maple block which worked for many decades.

> As far as I have been able to tell, the thickest block I can get is
> 1-1/2".  It will put quite a bit more pinblock area in the piano that
> I originally had, but I am uncertain as to what kind of wood to add
> to the back of the new pinblock.  It has to be a board planed down so
> that when the pinblock is installed, it will be in the proper place.
> I was thinking maple.  The wrong choice here would spell disaster.
> Help!

To replace such an upright pin block and any other upright pin block
you can chisel or saw the old one out at the glue seam depending on the
tenacity of the glue.  Next,  dress everything down smooth and even.
Glue the new one in place and I often use some screws to make sure it
stays.

Now, before this process, you must measure the thickness of the top
area of the whole back with the untouched old pin block in place.
Measure in several places as some of them were not perfectly  square
and make sure the new one is identical to the original.  If you need to
remove the spacer you can use any good cabinet wood.

Some pianos did not have the spacer and just dadoed out the upright
timbers so that there were open air pockets between pinblock, back
fascia, and side upright timbers.  Poplar, oak, birch, ash may all be
used equally well.  The maple is only needed for the  pins themselves.

> It needs the soundboard replaced.  That requires special presses
> and about $3000, I was told.

They were trying to discourage you or sell you a new piano.  You can
replace a soundboard without the presses, but you do need a dry room.
This is a room to put the piano in with 0% humidity.  If you do
soundboards you need one of these anyway.

As with any soundboard repair, this dry room is necessary to shrink the
soundboard so you can glue it in place.  When the glue is dry and the
piano comes out of the dry room, the soundboard, which already had
crown when dry, will soon have more crown from the ambient humidity of
the room.

The presses are great for when you do hundreds of boards.  However,
I do not replace the soundboard unless someone has driven a truck
through the old one.  90% of them can be repaired with MUCH better tone
than you have from any new board.  The old ones MUST be recrowned,
however.

I hope this helps.

D.L. Bullock Piano World St. Louis