Ross,
From American Wooden Planes, Benson & M'Call, made planes in Albany NY in 1842. One year partnerships can be an indication of rarity. The rating for this plane is two stars, indicating that when a survey of tool collectors was made umpteen years ago, they estimated[/u] 100-250 examples were known.
From Directory of American Toolmakers, Nash was a known plane iron maker but the DAT doesnt report a date. Jones Nash was cited as a mark but they suggest it might have been Jones & Nash. Robert S. Jones was also an iron maker and no date is listed.
You might want to find a plane collector from the Albany region. They might be as interested in acquiring this plane as I would be interested in acquiring planes from Virginia or Washington DC. Yes its hard to believe that something good came out of Wash DC but that was back in 1855-1860.
John