Regarding tuning, I have seen two pianos without pin blocks.  One was
a Mason and Hamlin grand, and the other was an upright.  Instead of
a pinblock, the strings terminated at a turnbuckle of sorts.  The string
looped through a hole in a screw.  The screw itself was passed through
a projection in the iron plate (part of the main plate).  To tune the
piano turn the nut.  The nut which anchored the screw to the plate was
tightened or loosened to change the pitch.  There was a small wrench
included inside a pocket in the case.  In case the picture is not
clear, the screw in a straight line with the string, simply pulling
it in a straight line.

The system looked so simple and easy to work on.  Replacing a string
would have been a breeze.  The pianos were in tune and had normal tone
although both were old.  The upright was probably 1900 or so.  It makes
one wonder why this simple system did not catch on.  It would have been
far cheaper than the normal wooden pinblock.

Unrelated, there is a ship's piano with the fold-up keyboard for sale
in Petaluma CA.  It is a Bord, and has been sitting there for ages.
I don't think ship's pianos are all that rare, as several appeared in
the catalogues put out in the 1970s by Hathaway and Bowers.

Bill Chapman