Updated through online information from James R. Stettner.
Updated through online information from Scot Huntington. -- The 1850 William A. Johnson Op. 16 in the Union Church of Heath, Massachusetts is the oldest known extant Johnson.
Updated through information posted to PIPORG-L October 6, by David King: "There's an 1857 Johnson in Montague, MA, a few miles from here with a centered 13-note board."
Status Note: There 1986
Oldest existing unaltered Johnson. Restored c. 1984 by Czelusniak et Dugal. Ded. 11 Nov 1984 by Mr. And Mrs. Grant Moss.