A Google search on "Brandis sextant" yielded some results.
http://www.worthpoint.com/worthopedia/vintage-1938-us-navy-sextant-no-4267-brandisBrandis 4765, U.S. Navy Sextant Brandis & Sons, Brooklyn N.Y. Navy no. 4267
sold on eBay
http://www.worthpoint.com/worthopedia/us-navy-sexton-brandis-sons-new-yorkThe original box is very nice with nicely
dovetailed walls & brass hardware.
No numbers. Sold on eBay 08/18/2008
Seller Shawn at Cottonwood Village Antiques and Country Store 4300 Dawsonville Hwy Gainesville GA 30506
http://www.worthpoint.com/worthopedia/1921-us-navy-sextant-owned-by-enola-gay-admiralIncomplete information. This is a 1921 United States Navy Sextant made by Brandis & Sons of Brooklyn , New York. The sextant is marked US Navy #1146 on the bottom of the graduated scale. The case has the original Certificate of Inspection from August 27, 1921 for Brandis sextant number 1146.
Sold on eBay 12/11/2006
A possible expert ...
http://fer3.com/arc/m2.aspx?i=108211Bill Morris
Pukenui
New Zealand
"The first sextant was a ladder framed one by Brandis and Son Inc. The "Inc"
places it after 1916 and its serial number places its manufacturing date
around the First World War."
Navigation List archive:
www.fer3.com/arcTo post, email NavList---com
Book:
Sextants at Greenwich: a catalogue of the mariner's quadrants, mariner's ...
By W.F.J. Mörzer Bruyns, Richard Dunn
Another book - just published.
http://sextantbook.com/inside-the-book/See his article on rebuilding a Brandis aircraft sextant. Great photos.
http://sextantbook.com/category/aircraft-bubble-sextants/http://adsabs.harvard.edu/full/1919PA.....27..359WBrandis sextant 3257 noted as one of the instruments used to determine the longitude and latitude for observation of the eclipse of June 8, 1918.
http://www.liveauctioneers.com/h/item/7445914?ah=21-169a4&category=&itemtype=all(lot of 2) American ships sextant, Brandis & Sons Inc.
Sold May 2010 at Auston Auction Gallery, Austin, Texas for $250 512-258-5479
Decent pictures of box. Fair pics of sextant.
Maybe someone can track down the buyer and ask for numbers.