"According to a letter written to A. Phillips Hill on August 8, 1923 by Karl Heinkel, the instrument was in Mozart's house, purchased from Constanze von Nissen by Anton Andre. Henkel's father was helping Mr. Andre put Mozart's documents in order and Mr. Andre, not realizing their value, gave Mr. Henkel many of the old manuscripts and the violin. According to Henkel, Mr. Andre claimed that Mozart's widow had told him that the dalla Costa violin had belonged to Mozart and that Mozart had played it often."
More News About Mozart's Violin, Max Möller, Violins & Violinists, May-June, 1957, Chicago
"Experts are of the opinion that Mozart's Costa violin is original and complete in all essential parts: back, ribs, top, scroll and varnish. The whole instrument is in a good and absolutely playable condition. The body measures 357 mm in length, and has a maximum width of 204 mm and a minimum width of 112 mm. The top, as usual, is made from spruce and the back is made from remarkably beautifully flamed maple wood."