First, thanks to all who took the time to respond to my inquiry
regarding getting a 'nut' for the old round piano stool.  I wanted
to restore the stool and give it to my daughter along with a Beckman
Player Piano I'm attempting to get working again -- my first crack at
this type of activity  (By the way, it now does work with the aid of
a vacuum cleaner as a suction source, for which I owe John Tuttle many
thanks for helping me locate where some vacuum hoses go and learning
what the bellow boxes do below the keyboard.)

The stool has no sentimental value; I got it with another player
I purchased last week, which also needs considerable work and will
probably be the topic of future correspondence.  I just thought she'd
like one and wanted to keep it as close to the original construction
as possible.

John Tuttle's response was the only one which provided a total re-
placement of the screw mechanism for $55, which I thought was pretty
reasonable considering the machining necessary for the parts.  I was
considering this over the weekend and discussed it with my son and
daughter and their spouses who are all somewhat 'antique browsers' and
buyers, with limited budgets!  (Note: We had a family get-together this
weekend, and among other things we played the Beckman Player Piano with
great fun.)

They noted that they often see these types of piano stools in antique
shops around Bowie MD and Philadelphia PA for around $35 to $55,
depending on the condition.  I had thought these types of stools might
be worth over $100.  Obviously I shouldn't go antique buying by myself!

So our consensus was that since there wasn't any particular sentimental
value attached to the broken stool, perhaps it would be better to look
at those that might be available in some antique shops.  They might be
in better condition, and perhaps less than the cost of a replacement
swivel mechanism.

But another aspect had come up on MMD.  Larry Toto noted in MMD 990723
an interesting Acme Piano warehouse in Philadelphia, about a mile from
where my daughter lives.  Based on the info Larry provided, I surfed
the Web a bit and found that, according to the info provided by a web
search, the Acme Piano Company is located at 820 S. 2nd Street,
Philadelphia, PA 19147.  A different telephone number was given than
the one in Larry's correspondence.  The Web provided number is (215)
468-8766.

My daughter and son-in-law hope to check out the place next week if
their schedule permits.  Their focus (I hope) will be player pianos
and player parts, old swivel stools, and other mechanical music
devices/instruments ... if they survive the warehouse.  I forgot to
tell them to take a flashlight!  :-)  I'll let you all know what they
find out.

Thanks again to all for your interest and help.

Dale C. Houser