> I am not certain if I want to salvage these blocks, since I do not
> trust the inside valve seat insert he put in, and the white glue
> joints will be a nightmare to open.

Just throw the blocks into lacquer thinner and soak them until the glue
comes loose, and it will easily rub off with your finger.  I don't
believe the Bakelite seats will dissolve in lacquer thinner; they are
soluble in methanol or alcohol.  This may allow you to save some or all
of them.

It might be difficult to find someone who will trash a piano for the
valve blocks.  You might find someone who has a spare stack you might
buy, but I do not have one.

D. L. Bullock   Piano World St. Louis