Image by MyNeChimKi
This is a photograph of the original, but the description of the buttons for sale is:
As found on the staircases in both the east and west halls of Oatlands mansion, a mortgage button indicates that a home is paid in full. The mortgage button is handcrafted in Loudoun County, Virginia, from Oatlands boxwood.
Dating back to the mid-seventeenth century, the "mortgage button" is a long-standing New England tradition, which originated in Nantucket. When a home’s mortgage was fully paid, a hole was drilled in the top of the staircase banister or newel. The mortgage was either rolled up and placed inside the hole, or burned and its ashes were placed within. A button, usually made of whalebone, was scrimshawed with the date and owner’s initial and placed over the hole to seal its contents. from The Mortgage Button site
Perhaps Oatlands had to take out a 2nd mortgage and that’s why they have two mortgage buttons!
(available for purchase in the Oatlands Gift Shop)