I love when people sell things for the blind and say "see pictures"! Anyway, can someone please tell me what this is? I doubt it's a Perkins. Could it be a New Hall? I can't believe the price!
If it helps, here is a page on old braillewriters.
It's a long flat metal device, with 4 rows of small rectangular holes in it. It looks most like the "slate" mentioned on the page you linked to.
Hope this helps, I don't have any expertise in the matter!
https://sites.aph.org/museum-virtual-exhibit/vex2/376B949D-2710-4516-AF12-148244006218.htm