Pitch of 150-year-old piano; the square grand saga continues...

First, let me say thank you to all who commented on the possible value
of my recently acquired square grand piano.  I am especially grateful
to D.L. Bullock for his encouraging comments on the restoration of the
square grand.  Based on his input, and that of others, I decided to
take the next step, and have my favorite piano technician come and look
at the beast, which he did this morning.

Some of the fine points: The piano was actually made by Emerson of
Boston, and based on the serial number it should date to around 1853.
It has the name "Ditson" on the front, but this appears to be some sort
of store brand or some such thing.

The condition:  The rosewood outside is in mediocre shape, but should
be recoverable.  There is _no_ water damage, but some minor sunlight
damage to the veneer, and some of the trim is missing, all very
fixable.  The action has some broken springs, and a couple of the
hammers are broken, but repairable.  The felt on the hammers and
dampers will need replacing pretty much overall, but it looks like
I can get by without re-stringing, which will save a few dollars.

The big items are the good news:  The pin block is in very good shape,
and only a few of the pins are loose, and an experimental re-bore and
replacement procedure went quite well.  The bridge is in excellent
shape, and what little bow there is in the sounding board should be
easily taken care of with minor work.

So, let the games begin...

Now, on to my question:  Norm, the piano tech, indicates that the scale
this piano was tuned to was not A=440 Hz.  My question is:  Anyone have
a good idea of what it should be?

Norm says we *could* tune it to A=440, as the strings are not overly
tight at that pitch, but this worries him a bit, and both of us agree
that we would rather have a pitch that reflects the historical accuracy
the instrument is worthy of.  I realize I will probably get as many
numbers as answers on this one, but if anybody has a good idea of what
pitch to tune a piano made in 1853 to, I would like to hear it.  Thanks
in advance, and have a Merry Christmas!

Best Regards,
Jim Hendershot
Grants Pass, OR