Hello, Mark,  It is rather easy to tune a Wurlitzer harp.  It is just
chromatic, like a piano.  In fact, if I remember correctly, the music
was actually arranged by Whitlock's sister, who was a piano teacher.
Anyway, you can just tune it in sequence like any piano.

_But,_ and it is a big "but," be very careful of the tension on the
strings.  The Wurlitzer harp does not have an iron plate.  In fact,
it doesn't have anything even remotely similar to a plate.  It has
a pinblock at the top and a simple wooden box at the bottom, separated
by the sounding board.  So there is nothing very strong keeping the
strings from pulling the box loose and destroying the musical part of
the harp.  If nothing else, one-hundred-year-old wood and hide glue
make this an distinct possibility.

So, I would strongly recommend that your piano tuner tune the harp at
least one whole note low, or safer yet, two notes low.  I tune it
2-1/2 notes low.  That being said, the reference "Treasures of
Mechanical Music" says that the scale goes from F to E.  This makes
"Middle C" fall at string #32, counting from the left.

I'd recommend that string #34 be tuned to C [440]  and even that could
be tuned 50 cents flat.  If the harp is presently tuned closer to
C=#32, I would be hesitant to pull low strings much higher; it would be
better to have a lower tension all across the scale.

There is nothing about the tuning frequency in the original manual that
came with the harp.  Furthermore, back 100 years ago there wasn't
really a standard frequency like A=440 Hz that we use today.  In the
manual, there is a lengthy description of how to tune the harp that
I can send your piano tuner if he needs it.

Regards from USA
Craig Smith